diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
index 52e71fc22b79..7e65d05f3f43 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
@@ -1257,8 +1257,8 @@ public String toDefaultValue(CodegenProperty cp, Schema schema) {
         schema = ModelUtils.getReferencedSchema(this.openAPI, schema);
         if (ModelUtils.isArraySchema(schema)) {
             if (schema.getDefault() == null) {
-                // nullable or containerDefaultToNull set to true
-                if (cp.isNullable || containerDefaultToNull) {
+                // nullable or optional or containerDefaultToNull set to true
+                if (cp.isNullable || !cp.required || containerDefaultToNull) {
                     return null;
                 }
                 return getDefaultCollectionType(schema);
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/AbstractJavaCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/AbstractJavaCodegenTest.java
index a8ab5f30ee1b..294612e2f544 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/AbstractJavaCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/AbstractJavaCodegenTest.java
@@ -55,9 +55,9 @@ public class AbstractJavaCodegenTest {
         "3_0/mapSchemas", TestUtils.parseFlattenSpec("src/test/resources/3_0/mapSchemas.yaml"),
         "3_0/spring/date-time-parameter-types-for-testing", TestUtils.parseFlattenSpec("src/test/resources/3_0/spring/date-time-parameter-types-for-testing.yml")
     );
-    
+
     private AbstractJavaCodegen codegen;
-    
+
     /**
      * In TEST-NG, test class (and its fields) is only constructed once (vs. for every test in Jupiter),
      * using @BeforeMethod to have a fresh codegen mock for each test
@@ -65,7 +65,7 @@ public class AbstractJavaCodegenTest {
     @BeforeMethod void mockAbstractCodegen() {
         codegen = Mockito.mock(
             AbstractJavaCodegen.class, Mockito.withSettings().defaultAnswer(Answers.CALLS_REAL_METHODS).useConstructor()
-        );        
+        );
     }
 
     @Test
@@ -124,7 +124,7 @@ public void testPreprocessOpenApiIncludeAllMediaTypesInAcceptHeader() {
     @Test
     public void testPreprocessOpenAPINumVersion() {
         final OpenAPI openAPIOtherNumVersion = TestUtils.parseFlattenSpec("src/test/resources/2_0/duplicateOperationIds.yaml");
-        
+
         codegen.preprocessOpenAPI(openAPIOtherNumVersion);
 
         Assert.assertEquals(codegen.getArtifactVersion(), openAPIOtherNumVersion.getInfo().getVersion());
@@ -156,7 +156,7 @@ public void convertVarNameWithCaml() {
         Assert.assertEquals(codegen.toVarName("$name"), "$Name");
         Assert.assertEquals(codegen.toVarName("1AAaa"), "_1AAaa");
     }
-    
+
     @Test
     public void convertModelName() {
         Assert.assertEquals(codegen.toModelName("name"), "Name");
@@ -399,7 +399,7 @@ public void defaultVersionTest() {
         codegen.setArtifactVersion(null);
         OpenAPI api = TestUtils.createOpenAPI();
         api.getInfo().setVersion(null);
-        
+
         codegen.processOpts();
         codegen.preprocessOpenAPI(api);
 
@@ -412,7 +412,7 @@ public void snapshotVersionTest() {
         codegen.additionalProperties().put("snapshotVersion", "true");
         OpenAPI api = TestUtils.createOpenAPI();
         api.getInfo().setVersion(null);
-        
+
         codegen.processOpts();
         codegen.preprocessOpenAPI(api);
 
@@ -425,7 +425,7 @@ public void snapshotVersionOpenAPITest() {
         codegen.additionalProperties().put(CodegenConstants.SNAPSHOT_VERSION, "true");
         OpenAPI api = TestUtils.createOpenAPI();
         api.getInfo().setVersion("2.0");
-        
+
         codegen.processOpts();
         codegen.preprocessOpenAPI(api);
 
@@ -484,7 +484,7 @@ public void snapshotVersionAlreadySnapshotTest() {
 
         codegen.processOpts();
         codegen.preprocessOpenAPI(TestUtils.createOpenAPI());
-        
+
         Assert.assertEquals(codegen.getArtifactVersion(), "4.1.2-SNAPSHOT");
     }
 
@@ -537,11 +537,11 @@ public void toDefaultValueTest() {
 
         ModelUtils.setGenerateAliasAsModel(false);
         defaultValue = codegen.toDefaultValue(codegen.fromProperty("", schema), schema);
-        Assert.assertEquals(defaultValue, "new ArrayList<>()");
+        Assert.assertNull(defaultValue);
 
         ModelUtils.setGenerateAliasAsModel(true);
         defaultValue = codegen.toDefaultValue(codegen.fromProperty("", schema), schema);
-        Assert.assertEquals(defaultValue, "new ArrayList<>()");
+        Assert.assertNull(defaultValue);
 
         // Create a map schema with additionalProperties type set to array alias
         schema = new MapSchema().additionalProperties(new Schema<>().$ref("#/components/schemas/NestedArray"));
@@ -623,7 +623,7 @@ public void getTypeDeclarationGivenSchemaMappingTest() {
         codegen.schemaMapping().put("MyStringType", "com.example.foo");
         codegen.setOpenAPI(new OpenAPI().components(new Components().addSchemas("MyStringType", new StringSchema())));
         Schema<?> schema = new ArraySchema().items(new Schema<>().$ref("#/components/schemas/MyStringType"));
-        
+
         String defaultValue = codegen.getTypeDeclaration(schema);
 
         Assert.assertEquals(defaultValue, "List<com.example.foo>");
@@ -678,16 +678,16 @@ public void getTypeDeclarationTest() {
     @Test
     public void processOptsBooleanTrueFromString() {
         codegen.additionalProperties().put(CodegenConstants.SNAPSHOT_VERSION, "true");
-        
+
         codegen.preprocessOpenAPI(FLATTENED_SPEC.get("3_0/petstore"));
-        
+
         Assert.assertTrue((boolean) codegen.additionalProperties().get(CodegenConstants.SNAPSHOT_VERSION));
     }
 
     @Test
     public void processOptsBooleanTrueFromBoolean() {
         codegen.additionalProperties().put(CodegenConstants.SNAPSHOT_VERSION, true);
-        
+
         codegen.preprocessOpenAPI(FLATTENED_SPEC.get("3_0/petstore"));
 
         Assert.assertTrue((boolean) codegen.additionalProperties().get(CodegenConstants.SNAPSHOT_VERSION));
@@ -696,7 +696,7 @@ public void processOptsBooleanTrueFromBoolean() {
     @Test
     public void processOptsBooleanFalseFromString() {
         codegen.additionalProperties().put(CodegenConstants.SNAPSHOT_VERSION, "false");
-        
+
         codegen.preprocessOpenAPI(FLATTENED_SPEC.get("3_0/petstore"));
 
         Assert.assertFalse((boolean) codegen.additionalProperties().get(CodegenConstants.SNAPSHOT_VERSION));
@@ -705,16 +705,16 @@ public void processOptsBooleanFalseFromString() {
     @Test
     public void processOptsBooleanFalseFromBoolean() {
         codegen.additionalProperties().put(CodegenConstants.SNAPSHOT_VERSION, false);
-        
+
         codegen.preprocessOpenAPI(FLATTENED_SPEC.get("3_0/petstore"));
-        
+
         Assert.assertFalse((boolean) codegen.additionalProperties().get(CodegenConstants.SNAPSHOT_VERSION));
     }
 
     @Test
     public void processOptsBooleanFalseFromGarbage() {
         codegen.additionalProperties().put(CodegenConstants.SNAPSHOT_VERSION, "blibb");
-        
+
         codegen.preprocessOpenAPI(FLATTENED_SPEC.get("3_0/petstore"));
 
         Assert.assertFalse((boolean) codegen.additionalProperties().get(CodegenConstants.SNAPSHOT_VERSION));
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaModelEnumTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaModelEnumTest.java
index f0c11f141fad..ba297ac3fa9f 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaModelEnumTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaModelEnumTest.java
@@ -75,7 +75,7 @@ public void converterInArrayTest() {
         Assert.assertEquals(enumVar.dataType, "List<String>");
         Assert.assertEquals(enumVar.datatypeWithEnum, "List<NameEnum>");
         Assert.assertEquals(enumVar.name, "name");
-        Assert.assertEquals(enumVar.defaultValue, "new ArrayList<>()");
+        Assert.assertEquals(enumVar.defaultValue, null);
         Assert.assertEquals(enumVar.baseType, "List");
         Assert.assertTrue(enumVar.isEnum);
 
@@ -108,7 +108,7 @@ public void converterInArrayInArrayTest() {
         Assert.assertEquals(enumVar.dataType, "List<List<String>>");
         Assert.assertEquals(enumVar.datatypeWithEnum, "List<List<NameEnum>>");
         Assert.assertEquals(enumVar.name, "name");
-        Assert.assertEquals(enumVar.defaultValue, "new ArrayList<>()");
+        Assert.assertEquals(enumVar.defaultValue, null);
         Assert.assertEquals(enumVar.baseType, "List");
         Assert.assertTrue(enumVar.isEnum);
 
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaModelTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaModelTest.java
index 91c36f642936..dc23cc5dd524 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaModelTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaModelTest.java
@@ -132,7 +132,7 @@ public void listPropertyTest() {
         Assert.assertEquals(property.setter, "setUrls");
         Assert.assertEquals(property.dataType, "List<String>");
         Assert.assertEquals(property.name, "urls");
-        Assert.assertEquals(property.defaultValue, "new ArrayList<>()");
+        Assert.assertEquals(property.defaultValue, null);
         Assert.assertEquals(property.baseType, "List");
         Assert.assertEquals(property.containerType, "array");
         Assert.assertFalse(property.required);
@@ -164,7 +164,7 @@ public void setPropertyTest() {
         Assert.assertEquals(property.setter, "setUrls");
         Assert.assertEquals(property.dataType, "Set<String>");
         Assert.assertEquals(property.name, "urls");
-        Assert.assertEquals(property.defaultValue, "new LinkedHashSet<>()");
+        Assert.assertEquals(property.defaultValue, null);
         Assert.assertEquals(property.baseType, "Set");
         Assert.assertEquals(property.containerType, "set");
         Assert.assertFalse(property.required);
@@ -250,7 +250,7 @@ public void list2DPropertyTest() {
         Assert.assertEquals(property.setter, "setList2D");
         Assert.assertEquals(property.dataType, "List<List<Pet>>");
         Assert.assertEquals(property.name, "list2D");
-        Assert.assertEquals(property.defaultValue, "new ArrayList<>()");
+        Assert.assertEquals(property.defaultValue, null);
         Assert.assertEquals(property.baseType, "List");
         Assert.assertEquals(property.containerType, "array");
         Assert.assertFalse(property.required);
@@ -335,7 +335,7 @@ public void complexListPropertyTest() {
         Assert.assertEquals(property.setter, "setChildren");
         Assert.assertEquals(property.dataType, "List<Children>");
         Assert.assertEquals(property.name, "children");
-        Assert.assertEquals(property.defaultValue, "new ArrayList<>()");
+        Assert.assertEquals(property.defaultValue, null);
         Assert.assertEquals(property.baseType, "List");
         Assert.assertEquals(property.containerType, "array");
         Assert.assertFalse(property.required);
@@ -398,7 +398,7 @@ public void complexArrayPropertyTest() {
         Assert.assertEquals(property.setter, "setChildren");
         Assert.assertEquals(property.dataType, "List<Children>");
         Assert.assertEquals(property.name, "children");
-        Assert.assertEquals(property.defaultValue, "new ArrayList<>()");
+        Assert.assertEquals(property.defaultValue, null);
         Assert.assertEquals(property.baseType, "List");
         Assert.assertEquals(property.containerType, "array");
         Assert.assertFalse(property.required);
@@ -431,7 +431,7 @@ public void complexSetPropertyTest() {
         Assert.assertEquals(property.setter, "setChildren");
         Assert.assertEquals(property.dataType, "Set<Children>");
         Assert.assertEquals(property.name, "children");
-        Assert.assertEquals(property.defaultValue, "new LinkedHashSet<>()");
+        Assert.assertEquals(property.defaultValue, null);
         Assert.assertEquals(property.baseType, "Set");
         Assert.assertEquals(property.containerType, "set");
         Assert.assertFalse(property.required);
@@ -468,7 +468,7 @@ public void arrayModelWithItemNameTest() {
         Assert.assertEquals(property.setter, "setChildren");
         Assert.assertEquals(property.dataType, "List<Child>");
         Assert.assertEquals(property.name, "children");
-        Assert.assertEquals(property.defaultValue, "new ArrayList<>()");
+        Assert.assertEquals(property.defaultValue, null);
         Assert.assertEquals(property.baseType, "List");
         Assert.assertEquals(property.containerType, "array");
         Assert.assertFalse(property.required);
@@ -976,7 +976,7 @@ public void modelWithWrappedXmlTest() {
         Assert.assertEquals(property2.setter, "setArray");
         Assert.assertEquals(property2.dataType, "List<String>");
         Assert.assertEquals(property2.name, "array");
-        Assert.assertEquals(property2.defaultValue, "new ArrayList<>()");
+        Assert.assertEquals(property2.defaultValue, null);
         Assert.assertEquals(property2.baseType, "List");
         Assert.assertTrue(property2.isContainer);
         Assert.assertTrue(property2.isXmlWrapped);
@@ -1131,14 +1131,14 @@ public void stringPropertyTest() {
         Assert.assertEquals(cp.maxLength, Integer.valueOf(10));
         Assert.assertEquals(cp.pattern, "^[A-Z]+$");
     }
-    
+
     @Test(description = "convert string property with password format")
     public void stringPropertyPasswordFormatTest() {
         OpenAPI openAPI = TestUtils.createOpenAPI();
         final Schema property = new StringSchema().format("password");
         final DefaultCodegen codegen = new JavaClientCodegen();
         codegen.setOpenAPI(openAPI);
-        
+
         final CodegenProperty cp = codegen.fromProperty("somePropertyWithPasswordFormat", property);
         Assert.assertEquals(cp.isPassword, true);
     }
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java
index 495a5f153c42..c19392750a8e 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/spring/SpringCodegenTest.java
@@ -854,7 +854,7 @@ public void shouldUseTagsForClassname() throws IOException {
 
         DefaultGenerator generator = new DefaultGenerator();
         generator.setGenerateMetadata(false);
-        
+
         Map<String, File> files = generator.opts(input).generate().stream()
               .collect(Collectors.toMap(File::getName, Function.identity()));
 
@@ -1664,7 +1664,7 @@ public void testOneOf5381() throws IOException {
         generator.setGeneratorPropertyDefault(CodegenConstants.MODEL_TESTS, "false");
         generator.setGeneratorPropertyDefault(CodegenConstants.MODEL_DOCS, "false");
         generator.setGeneratorPropertyDefault(CodegenConstants.LEGACY_DISCRIMINATOR_BEHAVIOR, "false");
-        
+
         codegen.setUseOneOfInterfaces(true);
         codegen.setLegacyDiscriminatorBehavior(false);
 
@@ -2680,7 +2680,7 @@ public void contractWithResolvedInnerEnumContainsEnumConverter() throws IOExcept
         final ClientOptInput clientOptInput = configurator.toClientOptInput();
         DefaultGenerator generator = new DefaultGenerator();
         generator.setGenerateMetadata(false);
-        
+
         Map<String, File> files = generator.opts(clientOptInput).generate().stream()
                 .collect(Collectors.toMap(File::getName, Function.identity()));
 
@@ -2705,7 +2705,7 @@ public void shouldUseTheSameTagNameForTheInterfaceAndTheMethod_issue11570() thro
     @Test
     public void shouldGenerateConstructorWithOnlyRequiredParameters() throws IOException {
         final Map<String, File> output = generateFromContract(
-            "src/test/resources/3_0/spring/issue_9789.yml", 
+            "src/test/resources/3_0/spring/issue_9789.yml",
             SPRING_BOOT,
             Map.of(GENERATE_CONSTRUCTOR_WITH_ALL_ARGS, "false")
         );
@@ -4281,7 +4281,7 @@ public void testModelsWithNoneOptionalAndNoneOpenApiNullable() throws IOExceptio
         assertMethod(javaFileAssert, BigDecimal.class, "numberMaxNullable");
 
     }
-    
+
     private void assertOptionalMethod(JavaFileAssert javaFileAssert, Class<?> type, String expectedName, String getterReturnType){
         assertOptionalMethod(javaFileAssert, type.getSimpleName(), expectedName, getterReturnType);
     }
@@ -4621,8 +4621,8 @@ public void generateAllArgsConstructor() throws IOException {
     @Test
     public void allOfDuplicatedProperties() throws IOException {
         Map<String, File> output = generateFromContract(
-            "src/test/resources/3_0/allOfDuplicatedProperties.yaml", 
-            SPRING_BOOT, 
+            "src/test/resources/3_0/allOfDuplicatedProperties.yaml",
+            SPRING_BOOT,
             Map.of(GENERATE_CONSTRUCTOR_WITH_ALL_ARGS, true, INTERFACE_ONLY, "true")
         );
 
@@ -4678,11 +4678,11 @@ public void testLombokAnnotations() throws IOException {
     @Test
     void testBuilderJavaSpring_noOptional() throws IOException {
         Map<String, File> files = generateFromContract(
-            "src/test/resources/3_0/java/builder.yaml", 
+            "src/test/resources/3_0/java/builder.yaml",
             SPRING_BOOT,
             Map.of(
-                GENERATE_BUILDERS, true, 
-                SpringCodegen.OPENAPI_NULLABLE, false, 
+                GENERATE_BUILDERS, true,
+                SpringCodegen.OPENAPI_NULLABLE, false,
                 SpringCodegen.USE_OPTIONAL, false,
                 INTERFACE_ONLY, "true"
             )
@@ -4707,7 +4707,7 @@ void testBuilderJavaSpring_noOptional() throws IOException {
     @Test
     void testBuilderJavaSpring_useOptional() throws IOException {
         Map<String, File> files = generateFromContract(
-            "src/test/resources/3_0/java/builder.yaml", 
+            "src/test/resources/3_0/java/builder.yaml",
             SPRING_BOOT,
             Map.of(
                 GENERATE_BUILDERS, true,
@@ -4757,12 +4757,12 @@ public void optionalListShouldBeEmpty() throws IOException {
         DefaultGenerator generator = new DefaultGenerator();
         generator.setGenerateMetadata(false); // skip metadata and ↓ only generate models
         generator.setGeneratorPropertyDefault(CodegenConstants.MODELS, "true");
-        
+
         Map<String, File> files = generator.opts(input).generate().stream()
                 .collect(Collectors.toMap(File::getName, Function.identity()));
 
         JavaFileAssert.assertThat(files.get("PetDto.java"))
-                .fileContains("private List<@Valid TagDto> tags = new ArrayList<>();")
+                .fileContains("private List<@Valid TagDto> tags;")
                 .fileContains("private List<String> photoUrls = new ArrayList<>();");
 
     }
@@ -4791,7 +4791,7 @@ public void testCollectionTypesWithDefaults_issue_18102() throws IOException {
         DefaultGenerator generator = new DefaultGenerator();
         generator.setGenerateMetadata(false); // skip metadata and ↓ only generate models
         generator.setGeneratorPropertyDefault(CodegenConstants.MODELS, "true");
-        
+
         Map<String, File> files = generator.opts(input).generate().stream()
                 .collect(Collectors.toMap(File::getName, Function.identity()));
 
@@ -4837,6 +4837,38 @@ public void shouldGenerateOptionalParameterTypesWhenUsingOptionalAndDelegate_iss
                 .toFileAssert();
     }
 
+    @Test
+    public void testCollectionTypesOptionalInitializedWithNull_issue_18735() throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        OpenAPI openAPI = new OpenAPIParser()
+                .readLocation("src/test/resources/3_0/java/issue_18735.yaml", null, new ParseOptions()).getOpenAPI();
+        SpringCodegen codegen = new SpringCodegen();
+        codegen.setLibrary(SPRING_CLOUD_LIBRARY);
+        codegen.setOutputDir(output.getAbsolutePath());
+        codegen.additionalProperties().put(CodegenConstants.MODEL_PACKAGE, "xyz.model");
+        codegen.additionalProperties().put(CodegenConstants.API_NAME_SUFFIX, "Controller");
+        codegen.additionalProperties().put(CodegenConstants.API_PACKAGE, "xyz.controller");
+        codegen.additionalProperties().put(CodegenConstants.MODEL_NAME_SUFFIX, "Dto");
+        codegen.setContainerDefaultToNull(false);
+
+
+        ClientOptInput input = new ClientOptInput()
+                .openAPI(openAPI)
+                .config(codegen);
+
+        DefaultGenerator generator = new DefaultGenerator();
+        Map<String, File> files = generator.opts(input).generate().stream()
+                .collect(Collectors.toMap(File::getName, Function.identity()));
+
+        JavaFileAssert.assertThat(files.get("PetDto.java"))
+                .fileContains("private List<@Valid TagDto> tags;")
+                .fileContains("private List<@Valid TagDto> tagsRequiredList = new ArrayList<>();")
+                .fileContains("private List<String> stringList;")
+                .fileContains("private List<String> stringRequiredList = new ArrayList<>();");
+    }
+
     @Test
     public void testEnumUnknownDefaultCaseDeserializationTrue_issue13241() throws IOException {
 
@@ -4906,7 +4938,7 @@ public void testEnumUnknownDefaultCaseDeserializationNotSet_issue13241() throws
             .hasAnnotation("JacksonXmlElementWrapper", Map.of("useWrapping", "false"))
             .toFileAssert()
 
-            // ↓ test custom element name (https://swagger.io/docs/specification/data-models/representing-xml/#:~:text=Change%20Element%20Names)    
+            // ↓ test custom element name (https://swagger.io/docs/specification/data-models/representing-xml/#:~:text=Change%20Element%20Names)
             .assertMethod("getStatus")
             .doesNotHaveAnnotation("XmlAttribute")
             .doesNotHaveAnnotation("XmlElementWrapper")
@@ -4914,7 +4946,7 @@ public void testEnumUnknownDefaultCaseDeserializationNotSet_issue13241() throws
             .doesNotHaveAnnotation("JacksonXmlElementWrapper")
             .hasAnnotation("JacksonXmlProperty", Map.of("localName", "\"PetStatus\""))
             .toFileAssert()
-            
+
             // ↓ test same-name wrapping element (https://swagger.io/docs/specification/data-models/representing-xml/#:~:text=Wrapping%20Arrays)
             //   maps to 3rd example in https://spec.openapis.org/oas/v3.0.0#xml-arrays
             .assertMethod("getPhotoUrls")
@@ -4951,7 +4983,7 @@ public void testEnumUnknownDefaultCaseDeserializationNotSet_issue13241() throws
             .hasAnnotation("JacksonXmlProperty", Map.of("localName", "\"yummy-yummy\""))
             .hasAnnotation("JacksonXmlElementWrapper", Map.of("localName", "\"yummy-yummy\""))
             .toFileAssert()
-            
+
             // ↓ internal xml-array element name (4th example in https://spec.openapis.org/oas/v3.0.0#xml-arrays)
             .assertMethod("getColors")
             .doesNotHaveAnnotation("XmlAttribute")
@@ -4960,7 +4992,7 @@ public void testEnumUnknownDefaultCaseDeserializationNotSet_issue13241() throws
             .hasAnnotation("JacksonXmlProperty", Map.of("localName", "\"color\""))
             .hasAnnotation("JacksonXmlElementWrapper", Map.of("localName", "\"colors\""))
             .toFileAssert()
-            
+
             // ↓ ignored external xml-array element name, non-wrapped (2nd example in https://spec.openapis.org/oas/v3.0.0#xml-arrays)
             .assertMethod("getCategories")
             .doesNotHaveAnnotation("XmlAttribute")
@@ -4980,7 +5012,7 @@ public void testEnumUnknownDefaultCaseDeserializationNotSet_issue13241() throws
             .hasAnnotation("JacksonXmlProperty", Map.of("localName", "\"item\""))
             .hasAnnotation("JacksonXmlElementWrapper", Map.of("localName", "\"activities-array\""));
     }
-    
+
     /**
      * Regression test for <a href="https://github.com/OpenAPITools/openapi-generator/issues/12804">#12804</a>
      */
diff --git a/modules/openapi-generator/src/test/resources/3_0/java/issue_18735.yaml b/modules/openapi-generator/src/test/resources/3_0/java/issue_18735.yaml
new file mode 100644
index 000000000000..7778ed5bfa55
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/java/issue_18735.yaml
@@ -0,0 +1,76 @@
+openapi: 3.0.0
+servers:
+  - url: 'http://petstore.swagger.io/v2'
+info:
+  description: >-
+    This is a sample server Petstore server. For this sample, you can use the api key
+    `special-key` to test the authorization filters.
+  version: 1.0.0
+  title: OpenAPI Petstore
+  license:
+    name: Apache-2.0
+    url: 'https://www.apache.org/licenses/LICENSE-2.0.html'
+paths:
+  '/pet/{petId}':
+    get:
+      tags:
+        - pet
+      summary: Find pet by ID
+      description: Returns a single pet
+      operationId: getPetById
+      parameters:
+        - name: petId
+          in: path
+          description: ID of pet to return
+          required: true
+          schema:
+            type: integer
+            format: int64
+      responses:
+        '200':
+          description: successful operation
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Pet'
+        '400':
+          description: Invalid ID supplied
+        '404':
+          description: Pet not found
+components:
+  schemas:
+    Tag:
+      title: Pet Tag
+      description: A tag for a pet
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+    Pet:
+      title: a Pet
+      description: A pet for sale in the pet store
+      type: object
+      required:
+        - tagsRequiredList
+        - stringRequiredList
+      properties:
+        tags:
+          type: array
+          items:
+            $ref: '#/components/schemas/Tag'
+        tagsRequiredList:
+          type: array
+          items:
+            $ref: '#/components/schemas/Tag'
+        stringList:
+          type: array
+          items:
+            type: string
+        stringRequiredList:
+          type: array
+          items:
+            type: string
+
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DefaultValue.java
index 6a097c965f7a..508e63dc39f5 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -99,7 +99,7 @@ public static ArrayStringEnumDefaultEnum fromValue(String value) {
   private List<Integer> arrayIntegerDefault = new ArrayList<>(Arrays.asList(1, 3));
 
   public static final String JSON_PROPERTY_ARRAY_STRING = "array_string";
-  private List<String> arrayString = new ArrayList<>();
+  private List<String> arrayString;
 
   public static final String JSON_PROPERTY_ARRAY_STRING_NULLABLE = "array_string_nullable";
   private JsonNullable<List<String>> arrayStringNullable = JsonNullable.<List<String>>undefined();
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
index c5bb883ac0f9..1c2bc2da0e79 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
@@ -57,7 +57,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index 1cee1fef3336..50ee5ffd8603 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -39,7 +39,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
   public static final String JSON_PROPERTY_VALUES = "values";
-  private List<String> values = new ArrayList<>();
+  private List<String> values;
 
   public TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter() {
   }
diff --git a/samples/client/echo_api/java/apache-httpclient/src/test/java/org/openapitools/client/CustomTest.java b/samples/client/echo_api/java/apache-httpclient/src/test/java/org/openapitools/client/CustomTest.java
index 368c9ec5ea99..66716d9f7e2d 100644
--- a/samples/client/echo_api/java/apache-httpclient/src/test/java/org/openapitools/client/CustomTest.java
+++ b/samples/client/echo_api/java/apache-httpclient/src/test/java/org/openapitools/client/CustomTest.java
@@ -187,7 +187,7 @@ public void testArrayDefaultValues() {
       Assertions.assertEquals( d.getArrayIntegerDefault().get( 1 ), Integer.valueOf( 3 ) );
 
       Assertions.assertNull( d.getArrayStringNullable() );
-      Assertions.assertEquals( d.getArrayString(), Collections.emptyList() );
+      Assertions.assertNull( d.getArrayString() );
 
       // test addItem
       d.addArrayStringEnumDefaultItem( DefaultValue.ArrayStringEnumDefaultEnum.UNCLASSIFIED );
@@ -230,10 +230,10 @@ public void testDefaultValuesSerializationWithEmptyPayload() throws IOException
       Assertions.assertEquals( d.getArrayIntegerDefault().get( 1 ), Integer.valueOf( 3 ) );
 
       Assertions.assertNull( d.getArrayStringNullable() );
-      Assertions.assertEquals( d.getArrayString(), Collections.emptyList() );
+      Assertions.assertNull( d.getArrayString() );
 
       Assertions.assertEquals( apiClient.getObjectMapper().writeValueAsString( d ),
-            "{\"array_string_enum_ref_default\":[\"success\",\"failure\"],\"array_string_enum_default\":[\"success\",\"failure\"],\"array_string_default\":[\"failure\",\"skipped\"],\"array_integer_default\":[1,3],\"array_string\":[]}" );
+            "{\"array_string_enum_ref_default\":[\"success\",\"failure\"],\"array_string_enum_default\":[\"success\",\"failure\"],\"array_string_default\":[\"failure\",\"skipped\"],\"array_integer_default\":[1,3]}" );
    }
 
    @Test
@@ -259,10 +259,10 @@ public void testDefaultValuesSerializationWithJSONString() throws IOException {
       Assertions.assertEquals( d.getArrayIntegerDefault().get( 1 ), Integer.valueOf( 3 ) );
 
       Assertions.assertNull( d.getArrayStringNullable() );
-      Assertions.assertEquals( d.getArrayString(), Collections.emptyList() );
+      Assertions.assertNull( d.getArrayString() );
 
       Assertions.assertEquals( apiClient.getObjectMapper().writeValueAsString( d ),
-            "{\"array_string_enum_ref_default\":[\"unclassified\"],\"array_string_enum_default\":[\"unclassified\"],\"array_string_default\":[\"failure\"],\"array_integer_default\":[1,3],\"array_string\":[]}" );
+            "{\"array_string_enum_ref_default\":[\"unclassified\"],\"array_string_enum_default\":[\"unclassified\"],\"array_string_default\":[\"failure\"],\"array_integer_default\":[1,3]}" );
    }
 
    @Test
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
index 6eca8d3374f8..43a330c35435 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -99,7 +99,7 @@ public ArrayStringEnumDefaultEnum read(final JsonReader jsonReader) throws IOExc
 
   public static final String SERIALIZED_NAME_ARRAY_STRING = "array_string";
   @SerializedName(SERIALIZED_NAME_ARRAY_STRING)
-  private List<String> arrayString = new ArrayList<>();
+  private List<String> arrayString;
 
   public static final String SERIALIZED_NAME_ARRAY_STRING_NULLABLE = "array_string_nullable";
   @SerializedName(SERIALIZED_NAME_ARRAY_STRING_NULLABLE)
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Pet.java
index 9eff7e479cc5..9e39c21fc2c6 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/Pet.java
@@ -50,7 +50,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index bc2e076e4784..1347d9372ccf 100644
--- a/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/feign-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -32,7 +32,7 @@
 public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
   public static final String SERIALIZED_NAME_VALUES = "values";
   @SerializedName(SERIALIZED_NAME_VALUES)
-  private List<String> values = new ArrayList<>();
+  private List<String> values;
 
   public TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter() {
   }
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DefaultValue.java
index 8a76e68aa234..d8a185ec0d0a 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -101,7 +101,7 @@ public static ArrayStringEnumDefaultEnum fromValue(String value) {
   private List<Integer> arrayIntegerDefault = new ArrayList<>(Arrays.asList(1, 3));
 
   public static final String JSON_PROPERTY_ARRAY_STRING = "array_string";
-  private List<String> arrayString = new ArrayList<>();
+  private List<String> arrayString;
 
   public static final String JSON_PROPERTY_ARRAY_STRING_NULLABLE = "array_string_nullable";
   private JsonNullable<List<String>> arrayStringNullable = JsonNullable.<List<String>>undefined();
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java
index 0b3ba525fd70..8ee721eb4b35 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/Pet.java
@@ -59,7 +59,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index b4ef260240b5..309b7efce334 100644
--- a/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/native/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -40,7 +40,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
   public static final String JSON_PROPERTY_VALUES = "values";
-  private List<String> values = new ArrayList<>();
+  private List<String> values;
 
   public TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter() { 
   }
diff --git a/samples/client/echo_api/java/native/src/test/java/org/openapitools/client/CustomTest.java b/samples/client/echo_api/java/native/src/test/java/org/openapitools/client/CustomTest.java
index e7c6c5e62509..1dd51c109cdd 100644
--- a/samples/client/echo_api/java/native/src/test/java/org/openapitools/client/CustomTest.java
+++ b/samples/client/echo_api/java/native/src/test/java/org/openapitools/client/CustomTest.java
@@ -213,7 +213,7 @@ public void testArrayDefaultValues() {
 
       Assertions.assertNull( d.getArrayStringNullable() );
       Assertions.assertNull( d.getArrayStringExtensionNullable() );
-      Assertions.assertEquals( d.getArrayString(), List.of() );
+      Assertions.assertNull( d.getArrayString() );
 
       // test addItem
       d.addArrayStringEnumDefaultItem( DefaultValue.ArrayStringEnumDefaultEnum.UNCLASSIFIED );
@@ -256,10 +256,10 @@ public void testDefaultValuesSerializationWithEmptyPayload() throws IOException
 
       Assertions.assertNull( d.getArrayStringNullable() );
       Assertions.assertNull( d.getArrayStringExtensionNullable() );
-      Assertions.assertEquals( d.getArrayString(), List.of() );
+      Assertions.assertNull( d.getArrayString() );
 
       Assertions.assertEquals( apiClient.getObjectMapper().writeValueAsString( d ),
-            "{\"array_string_enum_ref_default\":[\"success\",\"failure\"],\"array_string_enum_default\":[\"success\",\"failure\"],\"array_string_default\":[\"failure\",\"skipped\"],\"array_integer_default\":[1,3],\"array_string\":[]}" );
+            "{\"array_string_enum_ref_default\":[\"success\",\"failure\"],\"array_string_enum_default\":[\"success\",\"failure\"],\"array_string_default\":[\"failure\",\"skipped\"],\"array_integer_default\":[1,3]}" );
    }
 
    @Test
@@ -286,10 +286,10 @@ public void testDefaultValuesSerializationWithJSONString() throws IOException {
 
       Assertions.assertNull( d.getArrayStringNullable() );
       Assertions.assertNull( d.getArrayStringExtensionNullable() );
-      Assertions.assertEquals( d.getArrayString(), List.of() );
+      Assertions.assertNull( d.getArrayString() );
 
       Assertions.assertEquals( apiClient.getObjectMapper().writeValueAsString( d ),
-            "{\"array_string_enum_ref_default\":[\"unclassified\"],\"array_string_enum_default\":[\"unclassified\"],\"array_string_default\":[\"failure\"],\"array_integer_default\":[1,3],\"array_string\":[]}" );
+            "{\"array_string_enum_ref_default\":[\"unclassified\"],\"array_string_enum_default\":[\"unclassified\"],\"array_string_default\":[\"failure\"],\"array_integer_default\":[1,3]}" );
    }
 
    @Test
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Pet.java
index 9484a7c990b1..cb3717b7a82e 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/model/Pet.java
@@ -73,7 +73,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
index 4906270fec60..292ebae61a88 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -127,7 +127,7 @@ public static void validateJsonElement(JsonElement jsonElement) throws IOExcepti
 
   public static final String SERIALIZED_NAME_ARRAY_STRING = "array_string";
   @SerializedName(SERIALIZED_NAME_ARRAY_STRING)
-  private List<String> arrayString = new ArrayList<>();
+  private List<String> arrayString;
 
   public static final String SERIALIZED_NAME_ARRAY_STRING_NULLABLE = "array_string_nullable";
   @SerializedName(SERIALIZED_NAME_ARRAY_STRING_NULLABLE)
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
index 82fe4d6aa38f..5ad436b2a4e5 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
@@ -73,7 +73,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index 2d501a2fcb75..949162597b10 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -55,7 +55,7 @@
 public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
   public static final String SERIALIZED_NAME_VALUES = "values";
   @SerializedName(SERIALIZED_NAME_VALUES)
-  private List<String> values = new ArrayList<>();
+  private List<String> values;
 
   public TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter() {
   }
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DefaultValue.java
index 808b204b784c..a7ed9760f6ef 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -96,7 +96,7 @@ public static ArrayStringEnumDefaultEnum fromValue(String value) {
   private List<Integer> arrayIntegerDefault = new ArrayList<>(Arrays.asList(1, 3));
 
   public static final String JSON_PROPERTY_ARRAY_STRING = "array_string";
-  private List<String> arrayString = new ArrayList<>();
+  private List<String> arrayString;
 
   public static final String JSON_PROPERTY_ARRAY_STRING_NULLABLE = "array_string_nullable";
   private JsonNullable<List<String>> arrayStringNullable = JsonNullable.<List<String>>undefined();
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Pet.java
index 9497767a70c8..c5c59c3f1d54 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/Pet.java
@@ -54,7 +54,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index e0049b304004..ef384c479696 100644
--- a/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/restclient/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -36,7 +36,7 @@
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
   public static final String JSON_PROPERTY_VALUES = "values";
-  private List<String> values = new ArrayList<>();
+  private List<String> values;
 
   public TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter() {
   }
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DefaultValue.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DefaultValue.java
index 7352ecd6efb8..999e5c48df00 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DefaultValue.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/DefaultValue.java
@@ -96,7 +96,7 @@ public static ArrayStringEnumDefaultEnum fromValue(String value) {
   private List<Integer> arrayIntegerDefault = new ArrayList<>(Arrays.asList(1, 3));
 
   public static final String JSON_PROPERTY_ARRAY_STRING = "array_string";
-  private List<String> arrayString = new ArrayList<>();
+  private List<String> arrayString;
 
   public static final String JSON_PROPERTY_ARRAY_STRING_NULLABLE = "array_string_nullable";
   private JsonNullable<List<String>> arrayStringNullable = JsonNullable.<List<String>>undefined();
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
index b931a58a0ab8..63d5acc6ac44 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
@@ -54,7 +54,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
index 441bbdfca4fe..4a35e411aa26 100644
--- a/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
+++ b/samples/client/echo_api/java/resteasy/src/main/java/org/openapitools/client/model/TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter.java
@@ -36,7 +36,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter {
   public static final String JSON_PROPERTY_VALUES = "values";
-  private List<String> values = new ArrayList<>();
+  private List<String> values;
 
   public TestQueryStyleFormExplodeTrueArrayStringQueryObjectParameter() {
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index e36913d1116e..67c2c91c8dc7 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -39,7 +39,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 6ef62703acb5..9b570c23fadb 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -39,7 +39,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java
index 0e7a94872ba5..2f4c346d209c 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -41,13 +41,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java
index 8f880c4ebca9..a20c081ffe91 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -112,7 +112,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 8f3d89782c6b..371f4c606cc1 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -43,7 +43,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java
index 4e66146e05e2..28a9894a4964 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -82,7 +82,7 @@ public class NullableClass extends HashMap<String, Object> {
   private JsonNullable<List<Object>> arrayAndItemsNullableProp = JsonNullable.<List<Object>>undefined();
 
   public static final String JSON_PROPERTY_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
-  private List<Object> arrayItemsNullable = new ArrayList<>();
+  private List<Object> arrayItemsNullable;
 
   public static final String JSON_PROPERTY_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   private JsonNullable<Map<String, Object>> objectNullableProp = JsonNullable.<Map<String, Object>>undefined();
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index d4d85aa8977e..a13fc2997c8c 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -52,7 +52,7 @@ public class ObjectWithDeprecatedFields {
   private DeprecatedObject deprecatedRef;
 
   public static final String JSON_PROPERTY_BARS = "bars";
-  private List<String> bars = new ArrayList<>();
+  private List<String> bars;
 
   public ObjectWithDeprecatedFields() {
   }
diff --git a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
index b1642f2ede92..6d7f6801fe6e 100644
--- a/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/apache-httpclient/src/main/java/org/openapitools/client/model/Pet.java
@@ -60,7 +60,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index f9daf760155e..7e0fad741ec1 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -37,7 +37,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 14ceed519ab3..80d32aa34af7 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -37,7 +37,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
index 17ba00fc78c7..dcc9dc35011d 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -39,13 +39,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
index d6fbb8a06d3b..649da1502d97 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -110,7 +110,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index f3ebdeb279c6..4dd700ca7e46 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -41,7 +41,7 @@ public class FileSchemaTestClass {
   private File file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<File> files = new ArrayList<>();
+  private List<File> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
index 6ed5d6927a91..4cf1e99b22cb 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
@@ -58,7 +58,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
index 1e56ff0d3781..1c46a8b30d0a 100644
--- a/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/feign-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -77,7 +77,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   public static final String JSON_PROPERTY_WRAPPED_ARRAY = "wrapped_array";
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String JSON_PROPERTY_NAME_STRING = "name_string";
   private String nameString;
@@ -92,10 +92,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   public static final String JSON_PROPERTY_NAME_ARRAY = "name_array";
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String JSON_PROPERTY_NAME_WRAPPED_ARRAY = "name_wrapped_array";
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_STRING = "prefix_string";
   private String prefixString;
@@ -110,10 +110,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_ARRAY = "prefix_array";
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String JSON_PROPERTY_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_STRING = "namespace_string";
   private String namespaceString;
@@ -128,10 +128,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   public static final String JSON_PROPERTY_NAMESPACE_ARRAY = "namespace_array";
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_STRING = "prefix_ns_string";
   private String prefixNsString;
@@ -146,10 +146,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_NS_ARRAY = "prefix_ns_array";
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
   }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index e453caffe2fa..e5bcf0f72ef6 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index a731ccddb6f3..88da50b34754 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayTest.java
index 024c96810773..c0a93b5318d1 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -38,13 +38,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumArrays.java
index 63d80fda2ac4..772b93c5036d 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -109,7 +109,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 8ca06494efc7..4157687784bc 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -40,7 +40,7 @@ public class FileSchemaTestClass {
   private File file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<File> files = new ArrayList<>();
+  private List<File> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java
index cc141eace51f..f6440d04a12f 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -83,7 +83,7 @@ public class NullableClass extends HashMap<String, Object> {
   private JsonNullable<List<Object>> arrayAndItemsNullableProp = JsonNullable.<List<Object>>undefined();
 
   public static final String JSON_PROPERTY_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
-  private List<Object> arrayItemsNullable = new ArrayList<>();
+  private List<Object> arrayItemsNullable;
 
   public static final String JSON_PROPERTY_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   private JsonNullable<Map<String, Object>> objectNullableProp = JsonNullable.<Map<String, Object>>undefined();
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 6e92bb28a2fc..140914a28b3a 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -49,7 +49,7 @@ public class ObjectWithDeprecatedFields {
   private DeprecatedObject deprecatedRef;
 
   public static final String JSON_PROPERTY_BARS = "bars";
-  private List<String> bars = new ArrayList<>();
+  private List<String> bars;
 
   public ObjectWithDeprecatedFields() {
   }
diff --git a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Pet.java
index d820605b43af..c9bb6299618a 100644
--- a/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/feign/src/main/java/org/openapitools/client/model/Pet.java
@@ -57,7 +57,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 8feb9e018903..05d6a8b157e0 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 23629d1da5ae..f1d21467ace2 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayTest.java
index e09e6bd4797a..851f20f7023f 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -38,13 +38,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumArrays.java
index 01f7885a0fff..877dcb0a8ba7 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -109,7 +109,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index b3e7387cf6dc..c16372e986fd 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -40,7 +40,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Pet.java
index 97d3f950180f..23c7e6769da6 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/Pet.java
@@ -57,7 +57,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/XmlItem.java
index 91a1c08a1da3..a29195993cd7 100644
--- a/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/google-api-client/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -76,7 +76,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   public static final String JSON_PROPERTY_WRAPPED_ARRAY = "wrapped_array";
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String JSON_PROPERTY_NAME_STRING = "name_string";
   private String nameString;
@@ -91,10 +91,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   public static final String JSON_PROPERTY_NAME_ARRAY = "name_array";
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String JSON_PROPERTY_NAME_WRAPPED_ARRAY = "name_wrapped_array";
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_STRING = "prefix_string";
   private String prefixString;
@@ -109,10 +109,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_ARRAY = "prefix_array";
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String JSON_PROPERTY_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_STRING = "namespace_string";
   private String namespaceString;
@@ -127,10 +127,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   public static final String JSON_PROPERTY_NAMESPACE_ARRAY = "namespace_array";
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_STRING = "prefix_ns_string";
   private String prefixNsString;
@@ -145,10 +145,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_NS_ARRAY = "prefix_ns_array";
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
   }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index bcfcdeef4003..5a0a8d1c32be 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -38,7 +38,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() { 
   }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 4f1942c3bfcd..a127733e8b4b 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -38,7 +38,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() { 
   }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayTest.java
index 9c4ea9e26044..8fc68a243da5 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -40,13 +40,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() { 
   }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumArrays.java
index 95ac4e0ca6a0..e20ae95059a4 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -111,7 +111,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() { 
   }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index d981b37718fc..0c9aefeeb844 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -42,7 +42,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() { 
   }
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Pet.java
index 5c8e10bd79bf..39da36c2fd7f 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/Pet.java
@@ -59,7 +59,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/XmlItem.java
index ce76be296c6b..c23b91cd02d2 100644
--- a/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/jersey2-java8-localdatetime/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -78,7 +78,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   public static final String JSON_PROPERTY_WRAPPED_ARRAY = "wrapped_array";
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String JSON_PROPERTY_NAME_STRING = "name_string";
   private String nameString;
@@ -93,10 +93,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   public static final String JSON_PROPERTY_NAME_ARRAY = "name_array";
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String JSON_PROPERTY_NAME_WRAPPED_ARRAY = "name_wrapped_array";
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_STRING = "prefix_string";
   private String prefixString;
@@ -111,10 +111,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_ARRAY = "prefix_array";
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String JSON_PROPERTY_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_STRING = "namespace_string";
   private String namespaceString;
@@ -129,10 +129,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   public static final String JSON_PROPERTY_NAMESPACE_ARRAY = "namespace_array";
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_STRING = "prefix_ns_string";
   private String prefixNsString;
@@ -147,10 +147,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_NS_ARRAY = "prefix_ns_array";
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() { 
   }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index bcfcdeef4003..5a0a8d1c32be 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -38,7 +38,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() { 
   }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 4f1942c3bfcd..a127733e8b4b 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -38,7 +38,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() { 
   }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
index 9c4ea9e26044..8fc68a243da5 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -40,13 +40,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() { 
   }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
index 95ac4e0ca6a0..e20ae95059a4 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -111,7 +111,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() { 
   }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index d981b37718fc..0c9aefeeb844 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -42,7 +42,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() { 
   }
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
index 5c8e10bd79bf..39da36c2fd7f 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
@@ -59,7 +59,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/XmlItem.java
index ce76be296c6b..c23b91cd02d2 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -78,7 +78,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   public static final String JSON_PROPERTY_WRAPPED_ARRAY = "wrapped_array";
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String JSON_PROPERTY_NAME_STRING = "name_string";
   private String nameString;
@@ -93,10 +93,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   public static final String JSON_PROPERTY_NAME_ARRAY = "name_array";
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String JSON_PROPERTY_NAME_WRAPPED_ARRAY = "name_wrapped_array";
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_STRING = "prefix_string";
   private String prefixString;
@@ -111,10 +111,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_ARRAY = "prefix_array";
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String JSON_PROPERTY_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_STRING = "namespace_string";
   private String namespaceString;
@@ -129,10 +129,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   public static final String JSON_PROPERTY_NAMESPACE_ARRAY = "namespace_array";
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_STRING = "prefix_ns_string";
   private String prefixNsString;
@@ -147,10 +147,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_NS_ARRAY = "prefix_ns_array";
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() { 
   }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 214525fce5bc..48f5ea1b23f0 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -40,7 +40,7 @@
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() { 
   }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index c181c4836c05..8bc9e44af0f4 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -40,7 +40,7 @@
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() { 
   }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayTest.java
index 2dc2ed6d0d36..b8f0a149b18d 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -42,13 +42,13 @@
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() { 
   }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Drawing.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Drawing.java
index 192a1eec7964..bb3da7321b83 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Drawing.java
@@ -63,7 +63,7 @@ public class Drawing {
   private JsonNullable<NullableShape> nullableShape = JsonNullable.<NullableShape>undefined();
 
   public static final String JSON_PROPERTY_SHAPES = "shapes";
-  private List<Shape> shapes = new ArrayList<>();
+  private List<Shape> shapes;
 
   public Drawing() { 
   }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumArrays.java
index 04a6c2a55f8e..5e8033fd1f64 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -113,7 +113,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() { 
   }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index bf28111482f4..c75cddae9be2 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -44,7 +44,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<@Valid ModelFile> files = new ArrayList<>();
+  private List<@Valid ModelFile> files;
 
   public FileSchemaTestClass() { 
   }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NullableClass.java
index 82b9e0e852f3..192487ab816d 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -87,7 +87,7 @@ public class NullableClass {
   private JsonNullable<List<Object>> arrayAndItemsNullableProp = JsonNullable.<List<Object>>undefined();
 
   public static final String JSON_PROPERTY_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
-  private List<Object> arrayItemsNullable = new ArrayList<>();
+  private List<Object> arrayItemsNullable;
 
   public static final String JSON_PROPERTY_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   private JsonNullable<Map<String, Object>> objectNullableProp = JsonNullable.<Map<String, Object>>undefined();
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 997108d36a6d..20742b894d7e 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -56,7 +56,7 @@ public class ObjectWithDeprecatedFields {
 
   public static final String JSON_PROPERTY_BARS = "bars";
   @Deprecated
-  private List<String> bars = new ArrayList<>();
+  private List<String> bars;
 
   public ObjectWithDeprecatedFields() { 
   }
diff --git a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Pet.java
index d113905a2753..30d8c94e57c8 100644
--- a/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/jersey3/src/main/java/org/openapitools/client/model/Pet.java
@@ -58,7 +58,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 973a9eed51b3..2533d9e70da1 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -41,7 +41,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() { 
   }
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 1c6634533950..bb6a3e637dbc 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -41,7 +41,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() { 
   }
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java
index e149c67659ef..e5d56bed6699 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -43,13 +43,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() { 
   }
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Drawing.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Drawing.java
index bf1eb73ff570..9b57473ceba8 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Drawing.java
@@ -66,7 +66,7 @@ public class Drawing extends HashMap<String, Fruit> {
   private JsonNullable<NullableShape> nullableShape = JsonNullable.<NullableShape>undefined();
 
   public static final String JSON_PROPERTY_SHAPES = "shapes";
-  private List<Shape> shapes = new ArrayList<>();
+  private List<Shape> shapes;
 
   public Drawing() { 
   }
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java
index 9ccbf56245ca..b2e976b796e4 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -114,7 +114,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() { 
   }
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 85c17c8f4d88..061f2db14d77 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -45,7 +45,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() { 
   }
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java
index 1b4e531c738e..0fb0644a539d 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -88,7 +88,7 @@ public class NullableClass extends HashMap<String, Object> {
   private JsonNullable<List<Object>> arrayAndItemsNullableProp = JsonNullable.<List<Object>>undefined();
 
   public static final String JSON_PROPERTY_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
-  private List<Object> arrayItemsNullable = new ArrayList<>();
+  private List<Object> arrayItemsNullable;
 
   public static final String JSON_PROPERTY_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   private JsonNullable<Map<String, Object>> objectNullableProp = JsonNullable.<Map<String, Object>>undefined();
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 703a2b02066c..ce4a30c0d3d7 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -54,7 +54,7 @@ public class ObjectWithDeprecatedFields {
   private DeprecatedObject deprecatedRef;
 
   public static final String JSON_PROPERTY_BARS = "bars";
-  private List<String> bars = new ArrayList<>();
+  private List<String> bars;
 
   public ObjectWithDeprecatedFields() { 
   }
diff --git a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java
index c863d1f83269..3664307684a1 100644
--- a/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/native-async/src/main/java/org/openapitools/client/model/Pet.java
@@ -59,7 +59,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java
index 8611e23dcf0e..d3d4037c94ab 100644
--- a/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/native-jakarta/src/main/java/org/openapitools/client/model/Pet.java
@@ -59,7 +59,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 0e07f8caaa1e..b0d6f380caff 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -41,7 +41,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() { 
   }
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 69e6d70b5383..70248145bd42 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -41,7 +41,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() { 
   }
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java
index ceca4dbe4c08..1b4b9db6e02c 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -43,13 +43,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() { 
   }
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java
index 6fe7f3a3f678..393a4b03b0fc 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Drawing.java
@@ -66,7 +66,7 @@ public class Drawing extends HashMap<String, Fruit> {
   private JsonNullable<NullableShape> nullableShape = JsonNullable.<NullableShape>undefined();
 
   public static final String JSON_PROPERTY_SHAPES = "shapes";
-  private List<Shape> shapes = new ArrayList<>();
+  private List<Shape> shapes;
 
   public Drawing() { 
   }
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java
index b571239b3182..d5aef31b99a1 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -114,7 +114,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() { 
   }
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 75168b37b1d6..55479c097bfe 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -45,7 +45,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() { 
   }
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
index 3a0fcf856792..ad1a842aa198 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -88,7 +88,7 @@ public class NullableClass extends HashMap<String, Object> {
   private JsonNullable<List<Object>> arrayAndItemsNullableProp = JsonNullable.<List<Object>>undefined();
 
   public static final String JSON_PROPERTY_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
-  private List<Object> arrayItemsNullable = new ArrayList<>();
+  private List<Object> arrayItemsNullable;
 
   public static final String JSON_PROPERTY_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   private JsonNullable<Map<String, Object>> objectNullableProp = JsonNullable.<Map<String, Object>>undefined();
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index ad15dc8d484f..00831ebae842 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -54,7 +54,7 @@ public class ObjectWithDeprecatedFields {
   private DeprecatedObject deprecatedRef;
 
   public static final String JSON_PROPERTY_BARS = "bars";
-  private List<String> bars = new ArrayList<>();
+  private List<String> bars;
 
   public ObjectWithDeprecatedFields() { 
   }
diff --git a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java
index 34f167faba0b..270e9c103e23 100644
--- a/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/native/src/main/java/org/openapitools/client/model/Pet.java
@@ -59,7 +59,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AnyTypeTest.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AnyTypeTest.java
index ae76ee50e4a0..f9fc7d5edb5c 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AnyTypeTest.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/AnyTypeTest.java
@@ -60,11 +60,11 @@ public class AnyTypeTest {
 
   public static final String SERIALIZED_NAME_ARRAY_PROP = "array_prop";
   @SerializedName(SERIALIZED_NAME_ARRAY_PROP)
-  private List<String> arrayProp = new ArrayList<>();
+  private List<String> arrayProp;
 
   public static final String SERIALIZED_NAME_REF_ARRAY_PREFIX_ITEMS = "ref_array_prefix_items";
   @SerializedName(SERIALIZED_NAME_REF_ARRAY_PREFIX_ITEMS)
-  private List<String> refArrayPrefixItems = new ArrayList<>();
+  private List<String> refArrayPrefixItems;
 
   public AnyTypeTest() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ArrayOfSameRef.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ArrayOfSameRef.java
index 4eb7f3f7a76a..255dc7ad42ef 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ArrayOfSameRef.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/ArrayOfSameRef.java
@@ -56,15 +56,15 @@
 public class ArrayOfSameRef {
   public static final String SERIALIZED_NAME_ARRAY_FOO_ONE = "arrayFooOne";
   @SerializedName(SERIALIZED_NAME_ARRAY_FOO_ONE)
-  private List<Tag> arrayFooOne = new ArrayList<>();
+  private List<Tag> arrayFooOne;
 
   public static final String SERIALIZED_NAME_ARRAY_FOO_TWO = "arrayFooTwo";
   @SerializedName(SERIALIZED_NAME_ARRAY_FOO_TWO)
-  private List<Tag> arrayFooTwo = new ArrayList<>();
+  private List<Tag> arrayFooTwo;
 
   public static final String SERIALIZED_NAME_ARRAY_FOO_THREE = "arrayFooThree";
   @SerializedName(SERIALIZED_NAME_ARRAY_FOO_THREE)
-  private List<Tag> arrayFooThree = new ArrayList<>();
+  private List<Tag> arrayFooThree;
 
   public ArrayOfSameRef() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Pet.java
index 71e425deb930..e4777f1c7577 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/model/Pet.java
@@ -73,7 +73,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Pet.java
index 71e425deb930..e4777f1c7577 100644
--- a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/model/Pet.java
@@ -73,7 +73,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 44a1443bca4b..16574f505410 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -56,7 +56,7 @@
 public class ArrayOfArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_NUMBER)
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 214db5beec12..ac33308e54cc 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -56,7 +56,7 @@
 public class ArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_NUMBER = "ArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_NUMBER)
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayTest.java
index 4e70c39850bb..268e92484af1 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -56,15 +56,15 @@
 public class ArrayTest {
   public static final String SERIALIZED_NAME_ARRAY_OF_STRING = "array_of_string";
   @SerializedName(SERIALIZED_NAME_ARRAY_OF_STRING)
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER)
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL)
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumArrays.java
index 23d594105ae8..105bdf279497 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -163,7 +163,7 @@ public static void validateJsonElement(JsonElement jsonElement) throws IOExcepti
 
   public static final String SERIALIZED_NAME_ARRAY_ENUM = "array_enum";
   @SerializedName(SERIALIZED_NAME_ARRAY_ENUM)
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 864aab7928ae..93bf8e35d81a 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -60,7 +60,7 @@ public class FileSchemaTestClass {
 
   public static final String SERIALIZED_NAME_FILES = "files";
   @SerializedName(SERIALIZED_NAME_FILES)
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Pet.java
index 32e22f377d77..203a3de30f93 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/Pet.java
@@ -75,7 +75,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/XmlItem.java
index e7c723352f24..440b33f0e1a6 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -72,7 +72,7 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_WRAPPED_ARRAY = "wrapped_array";
   @SerializedName(SERIALIZED_NAME_WRAPPED_ARRAY)
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String SERIALIZED_NAME_NAME_STRING = "name_string";
   @SerializedName(SERIALIZED_NAME_NAME_STRING)
@@ -92,11 +92,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_NAME_ARRAY = "name_array";
   @SerializedName(SERIALIZED_NAME_NAME_ARRAY)
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String SERIALIZED_NAME_NAME_WRAPPED_ARRAY = "name_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAME_WRAPPED_ARRAY)
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_STRING = "prefix_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_STRING)
@@ -116,11 +116,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_PREFIX_ARRAY = "prefix_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_ARRAY)
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY)
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_STRING = "namespace_string";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_STRING)
@@ -140,11 +140,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_NAMESPACE_ARRAY = "namespace_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_ARRAY)
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY)
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_STRING = "prefix_ns_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_STRING)
@@ -164,11 +164,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_PREFIX_NS_ARRAY = "prefix_ns_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_ARRAY)
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY)
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Pet.java
index 71e425deb930..e4777f1c7577 100644
--- a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/model/Pet.java
@@ -73,7 +73,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Pet.java
index 71e425deb930..e4777f1c7577 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/Pet.java
@@ -73,7 +73,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases2.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases2.java
index 7d2ee7a697ae..3d91353c6d94 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases2.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/model/PetWithRequiredNullableCases2.java
@@ -73,7 +73,7 @@ public class PetWithRequiredNullableCases2 {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 85cbc7ee00d1..975b95069801 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -58,7 +58,7 @@
 public class ArrayOfArrayOfNumberOnly implements Parcelable {
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_NUMBER)
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 82d22a3a1365..2fd51d095e29 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -58,7 +58,7 @@
 public class ArrayOfNumberOnly implements Parcelable {
   public static final String SERIALIZED_NAME_ARRAY_NUMBER = "ArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_NUMBER)
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayTest.java
index a6ee476dd0d4..f79b0e750da0 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -58,15 +58,15 @@
 public class ArrayTest implements Parcelable {
   public static final String SERIALIZED_NAME_ARRAY_OF_STRING = "array_of_string";
   @SerializedName(SERIALIZED_NAME_ARRAY_OF_STRING)
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER)
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL)
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumArrays.java
index a2c83e4c4153..a67b74eee07c 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -165,7 +165,7 @@ public static void validateJsonElement(JsonElement jsonElement) throws IOExcepti
 
   public static final String SERIALIZED_NAME_ARRAY_ENUM = "array_enum";
   @SerializedName(SERIALIZED_NAME_ARRAY_ENUM)
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 541a5eb4c81f..b90937179ed7 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -62,7 +62,7 @@ public class FileSchemaTestClass implements Parcelable {
 
   public static final String SERIALIZED_NAME_FILES = "files";
   @SerializedName(SERIALIZED_NAME_FILES)
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Pet.java
index 5514b63bdd53..c336a3271744 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/Pet.java
@@ -77,7 +77,7 @@ public class Pet implements Parcelable {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/XmlItem.java
index 6424ebb7f6be..c4d77278fe76 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -74,7 +74,7 @@ public class XmlItem implements Parcelable {
 
   public static final String SERIALIZED_NAME_WRAPPED_ARRAY = "wrapped_array";
   @SerializedName(SERIALIZED_NAME_WRAPPED_ARRAY)
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String SERIALIZED_NAME_NAME_STRING = "name_string";
   @SerializedName(SERIALIZED_NAME_NAME_STRING)
@@ -94,11 +94,11 @@ public class XmlItem implements Parcelable {
 
   public static final String SERIALIZED_NAME_NAME_ARRAY = "name_array";
   @SerializedName(SERIALIZED_NAME_NAME_ARRAY)
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String SERIALIZED_NAME_NAME_WRAPPED_ARRAY = "name_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAME_WRAPPED_ARRAY)
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_STRING = "prefix_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_STRING)
@@ -118,11 +118,11 @@ public class XmlItem implements Parcelable {
 
   public static final String SERIALIZED_NAME_PREFIX_ARRAY = "prefix_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_ARRAY)
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY)
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_STRING = "namespace_string";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_STRING)
@@ -142,11 +142,11 @@ public class XmlItem implements Parcelable {
 
   public static final String SERIALIZED_NAME_NAMESPACE_ARRAY = "namespace_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_ARRAY)
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY)
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_STRING = "prefix_ns_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_STRING)
@@ -166,11 +166,11 @@ public class XmlItem implements Parcelable {
 
   public static final String SERIALIZED_NAME_PREFIX_NS_ARRAY = "prefix_ns_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_ARRAY)
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY)
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Pet.java
index 70150ecd80d1..d4696afcab0f 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/model/Pet.java
@@ -76,7 +76,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Pet.java
index 3128ff7b5a5a..7c5b8b973738 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/model/Pet.java
@@ -75,7 +75,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayDefault.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayDefault.java
index 47e05cbc8f4f..d58c7641e1f3 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayDefault.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayDefault.java
@@ -59,7 +59,7 @@ public class ArrayDefault {
 
   public static final String SERIALIZED_NAME_WITHOUT_DEFAULT = "WithoutDefault";
   @SerializedName(SERIALIZED_NAME_WITHOUT_DEFAULT)
-  private List<String> withoutDefault = new ArrayList<>();
+  private List<String> withoutDefault;
 
   public ArrayDefault() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index b27cb262af6d..ebf09e4f23d5 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -56,7 +56,7 @@
 public class ArrayOfArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_NUMBER)
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOf.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOf.java
index 2cd1e6454dc8..fecdd3f2ffea 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOf.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOf.java
@@ -64,7 +64,7 @@ public class ArrayOfInlineAllOf {
 
   public static final String SERIALIZED_NAME_ARRAY_ALLOF_DOG_PROPERTY = "array_allof_dog_property";
   @SerializedName(SERIALIZED_NAME_ARRAY_ALLOF_DOG_PROPERTY)
-  private List<ArrayOfInlineAllOfArrayAllofDogPropertyInner> arrayAllofDogProperty = new ArrayList<>();
+  private List<ArrayOfInlineAllOfArrayAllofDogPropertyInner> arrayAllofDogProperty;
 
   public ArrayOfInlineAllOf() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index ae52bba5e34a..8b22a9846aab 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -56,7 +56,7 @@
 public class ArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_NUMBER = "ArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_NUMBER)
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayTest.java
index 162a6aed9155..75888b1fa99b 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -56,15 +56,15 @@
 public class ArrayTest {
   public static final String SERIALIZED_NAME_ARRAY_OF_STRING = "array_of_string";
   @SerializedName(SERIALIZED_NAME_ARRAY_OF_STRING)
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER)
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL)
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Drawing.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Drawing.java
index a67974c7420a..8d67f987e3ca 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Drawing.java
@@ -72,7 +72,7 @@ public class Drawing {
 
   public static final String SERIALIZED_NAME_SHAPES = "shapes";
   @SerializedName(SERIALIZED_NAME_SHAPES)
-  private List<Shape> shapes = new ArrayList<>();
+  private List<Shape> shapes;
 
   public Drawing() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumArrays.java
index cf355dd35f65..dc08a00440c2 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -163,7 +163,7 @@ public static void validateJsonElement(JsonElement jsonElement) throws IOExcepti
 
   public static final String SERIALIZED_NAME_ARRAY_ENUM = "array_enum";
   @SerializedName(SERIALIZED_NAME_ARRAY_ENUM)
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 49e733beb545..cd1995ec41b3 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -60,7 +60,7 @@ public class FileSchemaTestClass {
 
   public static final String SERIALIZED_NAME_FILES = "files";
   @SerializedName(SERIALIZED_NAME_FILES)
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPet.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPet.java
index fa28e27b4b62..f226d76e1553 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPet.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPet.java
@@ -78,7 +78,7 @@ public class NewPet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NullableClass.java
index 2e20d23ff222..d95e3522fa80 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -93,7 +93,7 @@ public class NullableClass {
 
   public static final String SERIALIZED_NAME_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
   @SerializedName(SERIALIZED_NAME_ARRAY_ITEMS_NULLABLE)
-  private List<Object> arrayItemsNullable = new ArrayList<>();
+  private List<Object> arrayItemsNullable;
 
   public static final String SERIALIZED_NAME_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   @SerializedName(SERIALIZED_NAME_OBJECT_NULLABLE_PROP)
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index b7c088152b29..505728fac988 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -72,7 +72,7 @@ public class ObjectWithDeprecatedFields {
   public static final String SERIALIZED_NAME_BARS = "bars";
   @Deprecated
   @SerializedName(SERIALIZED_NAME_BARS)
-  private List<String> bars = new ArrayList<>();
+  private List<String> bars;
 
   public ObjectWithDeprecatedFields() {
   }
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
index 9d81b9be83ad..f82f85fa9647 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java
@@ -73,7 +73,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetComposition.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetComposition.java
index 3f8cdee6f982..3900d3bceb6c 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetComposition.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetComposition.java
@@ -73,7 +73,7 @@ public class PetComposition {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetRef.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetRef.java
index 5d972266c935..ebd8b32b058c 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetRef.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetRef.java
@@ -73,7 +73,7 @@ public class PetRef {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetUsingAllOf.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetUsingAllOf.java
index 109e13191710..134aaeb9e31d 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetUsingAllOf.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetUsingAllOf.java
@@ -73,7 +73,7 @@ public class PetUsingAllOf {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 511c787493a6..9997cbb56d20 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -39,7 +39,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index cd7565bd97cf..e42b637a59c9 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -39,7 +39,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java
index 01c64d05cc6a..fbd20a7e91f6 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -41,13 +41,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java
index aafc69878c1a..e1520907275e 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -112,7 +112,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 6145fb136f88..407ab66b1276 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -43,7 +43,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<@Valid ModelFile> files = new ArrayList<>();
+  private List<@Valid ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Pet.java
index ca885ceb945f..224a6364df0a 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/Pet.java
@@ -60,7 +60,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/XmlItem.java
index 5281d053045d..836d802c38b6 100644
--- a/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/rest-assured-jackson/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -79,7 +79,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   public static final String JSON_PROPERTY_WRAPPED_ARRAY = "wrapped_array";
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String JSON_PROPERTY_NAME_STRING = "name_string";
   private String nameString;
@@ -94,10 +94,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   public static final String JSON_PROPERTY_NAME_ARRAY = "name_array";
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String JSON_PROPERTY_NAME_WRAPPED_ARRAY = "name_wrapped_array";
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_STRING = "prefix_string";
   private String prefixString;
@@ -112,10 +112,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_ARRAY = "prefix_array";
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String JSON_PROPERTY_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_STRING = "namespace_string";
   private String namespaceString;
@@ -130,10 +130,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   public static final String JSON_PROPERTY_NAMESPACE_ARRAY = "namespace_array";
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_STRING = "prefix_ns_string";
   private String prefixNsString;
@@ -148,10 +148,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_NS_ARRAY = "prefix_ns_array";
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
   }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index db86c95f5057..c5a9071ab671 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 public class ArrayOfArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_NUMBER)
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 804b8e84152d..4f77143123c0 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 public class ArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_NUMBER = "ArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_NUMBER)
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java
index 22708f9642d4..f51c80223309 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -36,15 +36,15 @@
 public class ArrayTest {
   public static final String SERIALIZED_NAME_ARRAY_OF_STRING = "array_of_string";
   @SerializedName(SERIALIZED_NAME_ARRAY_OF_STRING)
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER)
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL)
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java
index 1d17001afbe0..d385874990bc 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -133,7 +133,7 @@ public ArrayEnumEnum read(final JsonReader jsonReader) throws IOException {
 
   public static final String SERIALIZED_NAME_ARRAY_ENUM = "array_enum";
   @SerializedName(SERIALIZED_NAME_ARRAY_ENUM)
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index fa4fa072836e..cda2c029ff80 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -40,7 +40,7 @@ public class FileSchemaTestClass {
 
   public static final String SERIALIZED_NAME_FILES = "files";
   @SerializedName(SERIALIZED_NAME_FILES)
-  private List<@Valid ModelFile> files = new ArrayList<>();
+  private List<@Valid ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java
index 8a3b933c0fc0..815c7dec4418 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java
@@ -55,7 +55,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java
index 4bd4719e3563..ee046ab2ef86 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -52,7 +52,7 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_WRAPPED_ARRAY = "wrapped_array";
   @SerializedName(SERIALIZED_NAME_WRAPPED_ARRAY)
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String SERIALIZED_NAME_NAME_STRING = "name_string";
   @SerializedName(SERIALIZED_NAME_NAME_STRING)
@@ -72,11 +72,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_NAME_ARRAY = "name_array";
   @SerializedName(SERIALIZED_NAME_NAME_ARRAY)
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String SERIALIZED_NAME_NAME_WRAPPED_ARRAY = "name_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAME_WRAPPED_ARRAY)
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_STRING = "prefix_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_STRING)
@@ -96,11 +96,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_PREFIX_ARRAY = "prefix_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_ARRAY)
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY)
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_STRING = "namespace_string";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_STRING)
@@ -120,11 +120,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_NAMESPACE_ARRAY = "namespace_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_ARRAY)
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY)
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_STRING = "prefix_ns_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_STRING)
@@ -144,11 +144,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_PREFIX_NS_ARRAY = "prefix_ns_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_ARRAY)
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY)
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
   }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 8feb9e018903..05d6a8b157e0 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 23629d1da5ae..f1d21467ace2 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayTest.java
index e09e6bd4797a..851f20f7023f 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -38,13 +38,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumArrays.java
index 01f7885a0fff..877dcb0a8ba7 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -109,7 +109,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index b3e7387cf6dc..c16372e986fd 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -40,7 +40,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NullableClass.java
index 3dedffa20417..1e4cfb5f9ab9 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -79,7 +79,7 @@ public class NullableClass extends HashMap<String, Object> {
   private JsonNullable<List<Object>> arrayAndItemsNullableProp = JsonNullable.<List<Object>>undefined();
 
   public static final String JSON_PROPERTY_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
-  private List<Object> arrayItemsNullable = new ArrayList<>();
+  private List<Object> arrayItemsNullable;
 
   public static final String JSON_PROPERTY_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   private JsonNullable<Map<String, Object>> objectNullableProp = JsonNullable.<Map<String, Object>>undefined();
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index d2ec47f7f4a9..7a950fdc2eb4 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -49,7 +49,7 @@ public class ObjectWithDeprecatedFields {
   private DeprecatedObject deprecatedRef;
 
   public static final String JSON_PROPERTY_BARS = "bars";
-  private List<String> bars = new ArrayList<>();
+  private List<String> bars;
 
   public ObjectWithDeprecatedFields() {
   }
diff --git a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
index 97d3f950180f..23c7e6769da6 100644
--- a/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resteasy/src/main/java/org/openapitools/client/model/Pet.java
@@ -57,7 +57,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Pet.java
index ad30a0e12883..39ee0981f5eb 100644
--- a/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resttemplate-jakarta/src/main/java/org/openapitools/client/model/Pet.java
@@ -54,7 +54,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Pet.java
index 4a0fda1e8126..86174361c461 100644
--- a/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resttemplate-swagger1/src/main/java/org/openapitools/client/model/Pet.java
@@ -57,7 +57,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Pet.java
index 739b196b2798..f389090a5f06 100644
--- a/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resttemplate-swagger2/src/main/java/org/openapitools/client/model/Pet.java
@@ -56,7 +56,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index a19856f86ea5..c1d1d1d795b9 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -44,7 +44,7 @@
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
   @XmlElement(name = "ArrayArrayNumber")
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index f054dbd8ee47..df495a0bd872 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -44,7 +44,7 @@
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
   @XmlElement(name = "ArrayNumber")
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayTest.java
index a594b2ceb9f7..71a6f089d996 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -46,15 +46,15 @@
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
   @XmlElement(name = "array_of_string")
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
   @XmlElement(name = "array_array_of_integer")
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
   @XmlElement(name = "array_array_of_model")
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumArrays.java
index 81113c78052c..9dd64e83f369 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -126,7 +126,7 @@ public static ArrayEnumEnum fromValue(String value) {
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
   @XmlElement(name = "array_enum")
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 1d6aee0c3e2a..9de193b6cc18 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -49,7 +49,7 @@ public class FileSchemaTestClass {
 
   public static final String JSON_PROPERTY_FILES = "files";
   @XmlElement(name = "files")
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NullableClass.java
index 7d57219e7e7a..0fb4ba25bcbe 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -96,7 +96,7 @@ public class NullableClass extends HashMap<String, Object> {
 
   public static final String JSON_PROPERTY_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
   @XmlElement(name = "array_items_nullable")
-  private List<Object> arrayItemsNullable = new ArrayList<>();
+  private List<Object> arrayItemsNullable;
 
   public static final String JSON_PROPERTY_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   @XmlElement(name = "object_nullable_prop")
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 3dfde08a6bd8..1e297b20bb43 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -60,7 +60,7 @@ public class ObjectWithDeprecatedFields {
 
   public static final String JSON_PROPERTY_BARS = "bars";
   @XmlElement(name = "bars")
-  private List<String> bars = new ArrayList<>();
+  private List<String> bars;
 
   public ObjectWithDeprecatedFields() {
   }
diff --git a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Pet.java
index c83a3282a2c2..fbf7f9e4b1ea 100644
--- a/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/resttemplate-withXml/src/main/java/org/openapitools/client/model/Pet.java
@@ -71,7 +71,7 @@ public class Pet {
   public static final String JSON_PROPERTY_TAGS = "tags";
   @XmlElement(name = "Tag")
   @XmlElementWrapper(name = "tag")
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index ed6db1e977ea..ee8c40d25c99 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -38,7 +38,7 @@
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index d7c2d2195534..4b36cdea601e 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -38,7 +38,7 @@
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayTest.java
index f63be19bf414..1720f9640d28 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -40,13 +40,13 @@
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumArrays.java
index e4e75c3dc24d..09451404cb1f 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -111,7 +111,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index e9e1efbe7a5e..930ffbf1e682 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -42,7 +42,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<@Valid ModelFile> files = new ArrayList<>();
+  private List<@Valid ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Pet.java
index a54e767ef188..5e2c454c950f 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/Pet.java
@@ -59,7 +59,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/XmlItem.java
index 79995f01c085..b486c73f435e 100644
--- a/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/retrofit2-play26/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -78,7 +78,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   public static final String JSON_PROPERTY_WRAPPED_ARRAY = "wrapped_array";
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String JSON_PROPERTY_NAME_STRING = "name_string";
   private String nameString;
@@ -93,10 +93,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   public static final String JSON_PROPERTY_NAME_ARRAY = "name_array";
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String JSON_PROPERTY_NAME_WRAPPED_ARRAY = "name_wrapped_array";
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_STRING = "prefix_string";
   private String prefixString;
@@ -111,10 +111,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_ARRAY = "prefix_array";
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String JSON_PROPERTY_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_STRING = "namespace_string";
   private String namespaceString;
@@ -129,10 +129,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   public static final String JSON_PROPERTY_NAMESPACE_ARRAY = "namespace_array";
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_STRING = "prefix_ns_string";
   private String prefixNsString;
@@ -147,10 +147,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_NS_ARRAY = "prefix_ns_array";
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
   }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 8318bced60b0..af718cbc768d 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -33,7 +33,7 @@
 public class ArrayOfArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_NUMBER)
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 40618d8b1f22..3a314de48e30 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -33,7 +33,7 @@
 public class ArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_NUMBER = "ArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_NUMBER)
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayTest.java
index b4c7f6316920..d09b50589123 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -33,15 +33,15 @@
 public class ArrayTest {
   public static final String SERIALIZED_NAME_ARRAY_OF_STRING = "array_of_string";
   @SerializedName(SERIALIZED_NAME_ARRAY_OF_STRING)
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER)
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL)
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumArrays.java
index 0506daec7083..fd156ca804bf 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -130,7 +130,7 @@ public ArrayEnumEnum read(final JsonReader jsonReader) throws IOException {
 
   public static final String SERIALIZED_NAME_ARRAY_ENUM = "array_enum";
   @SerializedName(SERIALIZED_NAME_ARRAY_ENUM)
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 11a735bc01e7..4be3aafbd228 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -37,7 +37,7 @@ public class FileSchemaTestClass {
 
   public static final String SERIALIZED_NAME_FILES = "files";
   @SerializedName(SERIALIZED_NAME_FILES)
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Pet.java
index 3d4846ab0b77..7bb7e12d8c3c 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/Pet.java
@@ -52,7 +52,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/XmlItem.java
index d6d590a40d2b..ce01cc9eafc3 100644
--- a/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/retrofit2/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -49,7 +49,7 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_WRAPPED_ARRAY = "wrapped_array";
   @SerializedName(SERIALIZED_NAME_WRAPPED_ARRAY)
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String SERIALIZED_NAME_NAME_STRING = "name_string";
   @SerializedName(SERIALIZED_NAME_NAME_STRING)
@@ -69,11 +69,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_NAME_ARRAY = "name_array";
   @SerializedName(SERIALIZED_NAME_NAME_ARRAY)
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String SERIALIZED_NAME_NAME_WRAPPED_ARRAY = "name_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAME_WRAPPED_ARRAY)
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_STRING = "prefix_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_STRING)
@@ -93,11 +93,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_PREFIX_ARRAY = "prefix_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_ARRAY)
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY)
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_STRING = "namespace_string";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_STRING)
@@ -117,11 +117,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_NAMESPACE_ARRAY = "namespace_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_ARRAY)
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY)
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_STRING = "prefix_ns_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_STRING)
@@ -141,11 +141,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_PREFIX_NS_ARRAY = "prefix_ns_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_ARRAY)
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY)
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 8318bced60b0..af718cbc768d 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -33,7 +33,7 @@
 public class ArrayOfArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_NUMBER)
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 40618d8b1f22..3a314de48e30 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -33,7 +33,7 @@
 public class ArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_NUMBER = "ArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_NUMBER)
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayTest.java
index b4c7f6316920..d09b50589123 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -33,15 +33,15 @@
 public class ArrayTest {
   public static final String SERIALIZED_NAME_ARRAY_OF_STRING = "array_of_string";
   @SerializedName(SERIALIZED_NAME_ARRAY_OF_STRING)
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER)
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL)
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumArrays.java
index 0506daec7083..fd156ca804bf 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -130,7 +130,7 @@ public ArrayEnumEnum read(final JsonReader jsonReader) throws IOException {
 
   public static final String SERIALIZED_NAME_ARRAY_ENUM = "array_enum";
   @SerializedName(SERIALIZED_NAME_ARRAY_ENUM)
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 11a735bc01e7..4be3aafbd228 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -37,7 +37,7 @@ public class FileSchemaTestClass {
 
   public static final String SERIALIZED_NAME_FILES = "files";
   @SerializedName(SERIALIZED_NAME_FILES)
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Pet.java
index 3d4846ab0b77..7bb7e12d8c3c 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/Pet.java
@@ -52,7 +52,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/XmlItem.java
index d6d590a40d2b..ce01cc9eafc3 100644
--- a/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/retrofit2rx2/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -49,7 +49,7 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_WRAPPED_ARRAY = "wrapped_array";
   @SerializedName(SERIALIZED_NAME_WRAPPED_ARRAY)
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String SERIALIZED_NAME_NAME_STRING = "name_string";
   @SerializedName(SERIALIZED_NAME_NAME_STRING)
@@ -69,11 +69,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_NAME_ARRAY = "name_array";
   @SerializedName(SERIALIZED_NAME_NAME_ARRAY)
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String SERIALIZED_NAME_NAME_WRAPPED_ARRAY = "name_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAME_WRAPPED_ARRAY)
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_STRING = "prefix_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_STRING)
@@ -93,11 +93,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_PREFIX_ARRAY = "prefix_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_ARRAY)
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY)
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_STRING = "namespace_string";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_STRING)
@@ -117,11 +117,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_NAMESPACE_ARRAY = "namespace_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_ARRAY)
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY)
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_STRING = "prefix_ns_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_STRING)
@@ -141,11 +141,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_PREFIX_NS_ARRAY = "prefix_ns_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_ARRAY)
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY)
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 8318bced60b0..af718cbc768d 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -33,7 +33,7 @@
 public class ArrayOfArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_NUMBER)
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 40618d8b1f22..3a314de48e30 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -33,7 +33,7 @@
 public class ArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_NUMBER = "ArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_NUMBER)
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayTest.java
index b4c7f6316920..d09b50589123 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -33,15 +33,15 @@
 public class ArrayTest {
   public static final String SERIALIZED_NAME_ARRAY_OF_STRING = "array_of_string";
   @SerializedName(SERIALIZED_NAME_ARRAY_OF_STRING)
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER)
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL)
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumArrays.java
index 0506daec7083..fd156ca804bf 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -130,7 +130,7 @@ public ArrayEnumEnum read(final JsonReader jsonReader) throws IOException {
 
   public static final String SERIALIZED_NAME_ARRAY_ENUM = "array_enum";
   @SerializedName(SERIALIZED_NAME_ARRAY_ENUM)
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index 11a735bc01e7..4be3aafbd228 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -37,7 +37,7 @@ public class FileSchemaTestClass {
 
   public static final String SERIALIZED_NAME_FILES = "files";
   @SerializedName(SERIALIZED_NAME_FILES)
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Pet.java
index 3d4846ab0b77..7bb7e12d8c3c 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/Pet.java
@@ -52,7 +52,7 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/XmlItem.java
index d6d590a40d2b..ce01cc9eafc3 100644
--- a/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/retrofit2rx3/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -49,7 +49,7 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_WRAPPED_ARRAY = "wrapped_array";
   @SerializedName(SERIALIZED_NAME_WRAPPED_ARRAY)
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String SERIALIZED_NAME_NAME_STRING = "name_string";
   @SerializedName(SERIALIZED_NAME_NAME_STRING)
@@ -69,11 +69,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_NAME_ARRAY = "name_array";
   @SerializedName(SERIALIZED_NAME_NAME_ARRAY)
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String SERIALIZED_NAME_NAME_WRAPPED_ARRAY = "name_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAME_WRAPPED_ARRAY)
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_STRING = "prefix_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_STRING)
@@ -93,11 +93,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_PREFIX_ARRAY = "prefix_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_ARRAY)
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_WRAPPED_ARRAY)
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_STRING = "namespace_string";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_STRING)
@@ -117,11 +117,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_NAMESPACE_ARRAY = "namespace_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_ARRAY)
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
   @SerializedName(SERIALIZED_NAME_NAMESPACE_WRAPPED_ARRAY)
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_STRING = "prefix_ns_string";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_STRING)
@@ -141,11 +141,11 @@ public class XmlItem {
 
   public static final String SERIALIZED_NAME_PREFIX_NS_ARRAY = "prefix_ns_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_ARRAY)
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
   @SerializedName(SERIALIZED_NAME_PREFIX_NS_WRAPPED_ARRAY)
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
   }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 8feb9e018903..05d6a8b157e0 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 23629d1da5ae..f1d21467ace2 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
index e09e6bd4797a..851f20f7023f 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -38,13 +38,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
index 01f7885a0fff..877dcb0a8ba7 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -109,7 +109,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index b3e7387cf6dc..c16372e986fd 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -40,7 +40,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
index 97d3f950180f..23c7e6769da6 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/Pet.java
@@ -57,7 +57,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
index 91a1c08a1da3..a29195993cd7 100644
--- a/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/vertx-no-nullable/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -76,7 +76,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   public static final String JSON_PROPERTY_WRAPPED_ARRAY = "wrapped_array";
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   public static final String JSON_PROPERTY_NAME_STRING = "name_string";
   private String nameString;
@@ -91,10 +91,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   public static final String JSON_PROPERTY_NAME_ARRAY = "name_array";
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   public static final String JSON_PROPERTY_NAME_WRAPPED_ARRAY = "name_wrapped_array";
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_STRING = "prefix_string";
   private String prefixString;
@@ -109,10 +109,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_ARRAY = "prefix_array";
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   public static final String JSON_PROPERTY_PREFIX_WRAPPED_ARRAY = "prefix_wrapped_array";
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_STRING = "namespace_string";
   private String namespaceString;
@@ -127,10 +127,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   public static final String JSON_PROPERTY_NAMESPACE_ARRAY = "namespace_array";
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   public static final String JSON_PROPERTY_NAMESPACE_WRAPPED_ARRAY = "namespace_wrapped_array";
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_STRING = "prefix_ns_string";
   private String prefixNsString;
@@ -145,10 +145,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   public static final String JSON_PROPERTY_PREFIX_NS_ARRAY = "prefix_ns_array";
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   public static final String JSON_PROPERTY_PREFIX_NS_WRAPPED_ARRAY = "prefix_ns_wrapped_array";
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
   }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 8feb9e018903..05d6a8b157e0 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 23629d1da5ae..f1d21467ace2 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayTest.java
index e09e6bd4797a..851f20f7023f 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -38,13 +38,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumArrays.java
index 01f7885a0fff..877dcb0a8ba7 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -109,7 +109,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index b3e7387cf6dc..c16372e986fd 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -40,7 +40,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NullableClass.java
index 3dedffa20417..1e4cfb5f9ab9 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -79,7 +79,7 @@ public class NullableClass extends HashMap<String, Object> {
   private JsonNullable<List<Object>> arrayAndItemsNullableProp = JsonNullable.<List<Object>>undefined();
 
   public static final String JSON_PROPERTY_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
-  private List<Object> arrayItemsNullable = new ArrayList<>();
+  private List<Object> arrayItemsNullable;
 
   public static final String JSON_PROPERTY_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   private JsonNullable<Map<String, Object>> objectNullableProp = JsonNullable.<Map<String, Object>>undefined();
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index d2ec47f7f4a9..7a950fdc2eb4 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -49,7 +49,7 @@ public class ObjectWithDeprecatedFields {
   private DeprecatedObject deprecatedRef;
 
   public static final String JSON_PROPERTY_BARS = "bars";
-  private List<String> bars = new ArrayList<>();
+  private List<String> bars;
 
   public ObjectWithDeprecatedFields() {
   }
diff --git a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Pet.java
index 97d3f950180f..23c7e6769da6 100644
--- a/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/vertx/src/main/java/org/openapitools/client/model/Pet.java
@@ -57,7 +57,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index 7d499a1107ca..c817e412cfb0 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 3f533f2c08c8..86a4a5fe2b79 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -36,7 +36,7 @@
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
   }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayTest.java
index 032de8c2e6c2..7a428c7e657e 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -38,13 +38,13 @@
 @jakarta.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
   }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumArrays.java
index dd5790ce1bba..e20286cf8037 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -109,7 +109,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
   }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index a9a6de91f76e..57a2dfbb92d6 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -40,7 +40,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() {
   }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NullableClass.java
index 1e5581a2cccd..c2b954a1a56e 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -79,7 +79,7 @@ public class NullableClass extends HashMap<String, Object> {
   private JsonNullable<List<Object>> arrayAndItemsNullableProp = JsonNullable.<List<Object>>undefined();
 
   public static final String JSON_PROPERTY_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
-  private List<Object> arrayItemsNullable = new ArrayList<>();
+  private List<Object> arrayItemsNullable;
 
   public static final String JSON_PROPERTY_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   private JsonNullable<Map<String, Object>> objectNullableProp = JsonNullable.<Map<String, Object>>undefined();
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index 18848db9e424..29087255dbed 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -49,7 +49,7 @@ public class ObjectWithDeprecatedFields {
   private DeprecatedObject deprecatedRef;
 
   public static final String JSON_PROPERTY_BARS = "bars";
-  private List<String> bars = new ArrayList<>();
+  private List<String> bars;
 
   public ObjectWithDeprecatedFields() {
   }
diff --git a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Pet.java
index 41cffd9b6608..1b1635d4d86f 100644
--- a/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/webclient-jakarta/src/main/java/org/openapitools/client/model/Pet.java
@@ -57,7 +57,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Pet.java
index 8c0e38dfb6a1..9f1d8ec879bc 100644
--- a/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-cloud-deprecated/src/main/java/org/openapitools/model/Pet.java
@@ -39,7 +39,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Pet.java
index bfd489d624cc..84c1105731f6 100644
--- a/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-cloud-feign-without-url/src/main/java/org/openapitools/model/Pet.java
@@ -39,7 +39,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Pet.java
index ac7f5ecbe696..47f0d9b51829 100644
--- a/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-cloud-tags/src/main/java/org/openapitools/model/Pet.java
@@ -39,7 +39,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
index bfd489d624cc..84c1105731f6 100644
--- a/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
@@ -39,7 +39,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 9c284fea7f5c..3b716af17bdb 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -24,7 +24,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 5bb985f23574..a788ad3cbdb8 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -24,7 +24,7 @@
 public class ArrayOfNumberOnly {
 
   
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayTest.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayTest.java
index 729a8bd33a58..8ad0bba460d0 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/ArrayTest.java
@@ -24,13 +24,13 @@
 public class ArrayTest {
 
   
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumArrays.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumArrays.java
index 0f27caa47014..e9a2fd7f7ffb 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/EnumArrays.java
@@ -96,7 +96,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 026dfc0f79f0..3948dcdb8370 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -26,7 +26,7 @@ public class FileSchemaTestClass {
   private File file;
 
   
-  private List<File> files = new ArrayList<>();
+  private List<File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Pet.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Pet.java
index 3b95f3d72e4c..6388036ca1f2 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/XmlItem.java b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/XmlItem.java
index b004f00712c9..312254e3aa70 100644
--- a/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/client/petstore/spring-http-interface-reactive/src/main/java/org/openapitools/model/XmlItem.java
@@ -32,7 +32,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -43,10 +43,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -57,10 +57,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -71,10 +71,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -85,10 +85,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
index cfe1625fe950..2ae5ef658def 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
@@ -26,7 +26,7 @@
 public class ArrayOfArrayOfNumberOnlyDto {
 
   
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnlyDto arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
index 9f6a8bfb6e46..4e649dbde183 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
@@ -26,7 +26,7 @@
 public class ArrayOfNumberOnlyDto {
 
   
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnlyDto arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayTestDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayTestDto.java
index 93a9c5aadef0..0fc87f6ad558 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayTestDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/ArrayTestDto.java
@@ -26,13 +26,13 @@
 public class ArrayTestDto {
 
   
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   
-  private List<List<ReadOnlyFirstDto>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirstDto>> arrayArrayOfModel;
 
   public ArrayTestDto arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumArraysDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumArraysDto.java
index c3fb96ea6a54..6dd6b5a4e501 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumArraysDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/EnumArraysDto.java
@@ -98,7 +98,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArraysDto justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
index 69ecbf5c1875..a1464ca4011c 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
@@ -28,7 +28,7 @@ public class FileSchemaTestClassDto {
   private FileDto file;
 
   
-  private List<FileDto> files = new ArrayList<>();
+  private List<FileDto> files;
 
   public FileSchemaTestClassDto file(FileDto file) {
     this.file = file;
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/PetDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/PetDto.java
index daf4efa69b2b..49587ca01cc7 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/PetDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/PetDto.java
@@ -40,7 +40,7 @@ public class PetDto {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   
-  private List<TagDto> tags = new ArrayList<>();
+  private List<TagDto> tags;
 
   /**
    * pet status in the store
diff --git a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/XmlItemDto.java b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/XmlItemDto.java
index 31f99e803311..d557adf1a473 100644
--- a/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/XmlItemDto.java
+++ b/samples/client/petstore/spring-http-interface/src/main/java/org/openapitools/model/XmlItemDto.java
@@ -34,7 +34,7 @@ public class XmlItemDto {
   private Boolean attributeBoolean;
 
   
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -45,10 +45,10 @@ public class XmlItemDto {
   private Boolean nameBoolean;
 
   
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -59,10 +59,10 @@ public class XmlItemDto {
   private Boolean prefixBoolean;
 
   
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -73,10 +73,10 @@ public class XmlItemDto {
   private Boolean namespaceBoolean;
 
   
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -87,10 +87,10 @@ public class XmlItemDto {
   private Boolean prefixNsBoolean;
 
   
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItemDto attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Pet.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Pet.java
index 2bbaa7e4745f..0f63f81a6aae 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger1/src/main/java/org/openapitools/client/model/Pet.java
@@ -59,7 +59,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Pet.java b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Pet.java
index 05abd30bbe51..a88b03d16399 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8-swagger2/src/main/java/org/openapitools/client/model/Pet.java
@@ -58,7 +58,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index bcfcdeef4003..5a0a8d1c32be 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -38,7 +38,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() { 
   }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 4f1942c3bfcd..a127733e8b4b 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -38,7 +38,7 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayOfNumberOnly {
   public static final String JSON_PROPERTY_ARRAY_NUMBER = "ArrayNumber";
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() { 
   }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
index 9c4ea9e26044..8fc68a243da5 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -40,13 +40,13 @@
 @javax.annotation.Generated(value = "org.openapitools.codegen.languages.JavaClientCodegen", comments = "Generator version: 7.7.0-SNAPSHOT")
 public class ArrayTest {
   public static final String JSON_PROPERTY_ARRAY_OF_STRING = "array_of_string";
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   public static final String JSON_PROPERTY_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
-  private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() { 
   }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java
index 431f46762b3f..a999ce1a4a1c 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Drawing.java
@@ -61,7 +61,7 @@ public class Drawing {
   private JsonNullable<NullableShape> nullableShape = JsonNullable.<NullableShape>undefined();
 
   public static final String JSON_PROPERTY_SHAPES = "shapes";
-  private List<Shape> shapes = new ArrayList<>();
+  private List<Shape> shapes;
 
   public Drawing() { 
   }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
index 95ac4e0ca6a0..e20ae95059a4 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -111,7 +111,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   public static final String JSON_PROPERTY_ARRAY_ENUM = "array_enum";
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() { 
   }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index d981b37718fc..0c9aefeeb844 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -42,7 +42,7 @@ public class FileSchemaTestClass {
   private ModelFile _file;
 
   public static final String JSON_PROPERTY_FILES = "files";
-  private List<ModelFile> files = new ArrayList<>();
+  private List<ModelFile> files;
 
   public FileSchemaTestClass() { 
   }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java
index a571fd2e905c..3f852ce6839f 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/NullableClass.java
@@ -85,7 +85,7 @@ public class NullableClass {
   private JsonNullable<List<Object>> arrayAndItemsNullableProp = JsonNullable.<List<Object>>undefined();
 
   public static final String JSON_PROPERTY_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
-  private List<Object> arrayItemsNullable = new ArrayList<>();
+  private List<Object> arrayItemsNullable;
 
   public static final String JSON_PROPERTY_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   private JsonNullable<Map<String, Object>> objectNullableProp = JsonNullable.<Map<String, Object>>undefined();
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
index a1156d77ea68..f735cd5b7b87 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java
@@ -54,7 +54,7 @@ public class ObjectWithDeprecatedFields {
 
   public static final String JSON_PROPERTY_BARS = "bars";
   @Deprecated
-  private List<String> bars = new ArrayList<>();
+  private List<String> bars;
 
   public ObjectWithDeprecatedFields() { 
   }
diff --git a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
index 29edda0c277d..30701170cd17 100644
--- a/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/openapi3/client/petstore/java/jersey2-java8/src/main/java/org/openapitools/client/model/Pet.java
@@ -56,7 +56,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String JSON_PROPERTY_TAGS = "tags";
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Pet.java
index 7f9a91f1be08..afe8f3b997cb 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Pet.java
@@ -36,7 +36,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Pet.java
index 8fa5b0091dcf..cd563a3ab943 100644
--- a/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-3/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Pet.java
index 3c1deb5719d2..0c61e923573f 100644
--- a/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-async/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Pet.java
index 3c1deb5719d2..0c61e923573f 100644
--- a/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-http-basic/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index a3e3f1b10250..ffbb8952dbcc 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7a8a52168934..baa0ed7c0e24 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayTest.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayTest.java
index b556efec6550..7640fad15268 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/ArrayTest.java
@@ -26,13 +26,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumArrays.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumArrays.java
index efa05bc32eab..0a69fb151098 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/EnumArrays.java
@@ -98,7 +98,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 0fafd2083e8b..4e0d7f7fa681 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -28,7 +28,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Pet.java
index b89fdac1060b..e10d842beb86 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/Pet.java
@@ -40,7 +40,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/XmlItem.java b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/XmlItem.java
index 8aa00e822f01..f194de7a4e28 100644
--- a/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/openapi3/client/petstore/spring-cloud-oas3-fakeapi/src/main/java/org/openapitools/model/XmlItem.java
@@ -34,7 +34,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -45,10 +45,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -59,10 +59,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -73,10 +73,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -87,10 +87,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Pet.java
index 68fa4c143f60..5140d83d46bb 100644
--- a/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud-spring-pageable/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
index 3c1deb5719d2..0c61e923573f 100644
--- a/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-cloud/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Pet.java
index 3c1deb5719d2..0c61e923573f 100644
--- a/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-stubs-skip-default-interface/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Pet.java
index 3c1deb5719d2..0c61e923573f 100644
--- a/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/client/petstore/spring-stubs/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Pet.java
index 3c1deb5719d2..0c61e923573f 100644
--- a/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/spring-boot-springdoc/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Pet.java
index aca357d364e5..d6706c16c3eb 100644
--- a/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot-3/src/main/java/org/openapitools/model/Pet.java
@@ -45,7 +45,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index a3e3f1b10250..ffbb8952dbcc 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7a8a52168934..baa0ed7c0e24 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
index b556efec6550..7640fad15268 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
@@ -26,13 +26,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
index efa05bc32eab..0a69fb151098 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
@@ -98,7 +98,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 0fafd2083e8b..4e0d7f7fa681 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -28,7 +28,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
index f9990b4d4b95..a4cba96ffa00 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
@@ -40,7 +40,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
index 8aa00e822f01..f194de7a4e28 100644
--- a/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/openapi3/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
@@ -34,7 +34,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -45,10 +45,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -59,10 +59,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -73,10 +73,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -87,10 +87,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index a3e3f1b10250..ffbb8952dbcc 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7a8a52168934..baa0ed7c0e24 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
index b556efec6550..7640fad15268 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
@@ -26,13 +26,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
index efa05bc32eab..0a69fb151098 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
@@ -98,7 +98,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 0fafd2083e8b..4e0d7f7fa681 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -28,7 +28,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
index f9990b4d4b95..a4cba96ffa00 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
@@ -40,7 +40,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
index 8aa00e822f01..f194de7a4e28 100644
--- a/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/openapi3/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
@@ -34,7 +34,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -45,10 +45,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -59,10 +59,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -73,10 +73,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -87,10 +87,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Pet.java
index 2cfd01b39027..68d8af937ef5 100644
--- a/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot-source/src/main/java/org/openapitools/model/Pet.java
@@ -36,7 +36,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Pet.java b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Pet.java
index 3c1deb5719d2..0c61e923573f 100644
--- a/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/openapi3/server/petstore/springboot/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Pet.java
index 14562f78fb37..bbf3fcee0c2e 100644
--- a/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/java-camel/src/main/java/org/openapitools/model/Pet.java
@@ -46,7 +46,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
index 83c75a242e8e..dab2aafb6ad0 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfArrayOfNumberOnly.java
@@ -11,7 +11,7 @@
 
 public class ArrayOfArrayOfNumberOnly   {
 
-    private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+    private List<List<BigDecimal>> arrayArrayNumber;
 
     /**
      * Default constructor.
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
index 971fb516ba0c..96ff5ea0a444 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayOfNumberOnly.java
@@ -11,7 +11,7 @@
 
 public class ArrayOfNumberOnly   {
 
-    private List<BigDecimal> arrayNumber = new ArrayList<>();
+    private List<BigDecimal> arrayNumber;
 
     /**
      * Default constructor.
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayTest.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayTest.java
index d94cad1da9a3..8112ec19d48a 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayTest.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ArrayTest.java
@@ -11,9 +11,9 @@
 
 public class ArrayTest   {
 
-    private List<String> arrayOfString = new ArrayList<>();
-    private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
-    private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+    private List<String> arrayOfString;
+    private List<List<Long>> arrayArrayOfInteger;
+    private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
     /**
      * Default constructor.
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumArrays.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumArrays.java
index 29d6ebaa8fb4..ba6203947fe2 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumArrays.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/EnumArrays.java
@@ -87,7 +87,7 @@ public static ArrayEnumEnum fromValue(String text) {
     }
 
 
-    private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+    private List<ArrayEnumEnum> arrayEnum;
 
     /**
      * Default constructor.
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
index 2b6964db9dec..34fbdce5ca9e 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/FileSchemaTestClass.java
@@ -12,7 +12,7 @@
 public class FileSchemaTestClass   {
 
     private ModelFile _file;
-    private List<@Valid ModelFile> files = new ArrayList<>();
+    private List<@Valid ModelFile> files;
 
     /**
      * Default constructor.
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NullableClass.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NullableClass.java
index 11e7e2ec0fd0..fa9e97a3c055 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NullableClass.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/NullableClass.java
@@ -24,7 +24,7 @@ public class NullableClass extends HashMap<String, Object>  {
     private OffsetDateTime datetimeProp;
     private List<Object> arrayNullableProp;
     private List<Object> arrayAndItemsNullableProp;
-    private List<Object> arrayItemsNullable = new ArrayList<>();
+    private List<Object> arrayItemsNullable;
     private Map<String, Object> objectNullableProp;
     private Map<String, Object> objectAndItemsNullableProp;
     private Map<String, Object> objectItemsNullable = new HashMap<>();
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
index 83bc634c1d6b..e66eb43c911f 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/ObjectWithDeprecatedFields.java
@@ -15,7 +15,7 @@ public class ObjectWithDeprecatedFields   {
     private String uuid;
     private BigDecimal id;
     private DeprecatedObject deprecatedRef;
-    private List<String> bars = new ArrayList<>();
+    private List<String> bars;
 
     /**
      * Default constructor.
diff --git a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Pet.java b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Pet.java
index 671a9be156dc..17dd8d5f5170 100644
--- a/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Pet.java
+++ b/samples/server/petstore/java-helidon-server/v3/se/src/main/java/org/openapitools/server/model/Pet.java
@@ -21,7 +21,7 @@ public class Pet   {
     private Category category;
     private String name;
     private Set<String> photoUrls = new LinkedHashSet<>();
-    private List<@Valid Tag> tags = new ArrayList<>();
+    private List<@Valid Tag> tags;
 
     /**
     * pet status in the store
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index fc7afaf4edc4..9ca14d4c4f80 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -25,7 +25,7 @@ public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArr
 
   public ArrayOfArrayOfNumberOnly addArrayArrayNumberItem(List<BigDecimal> arrayArrayNumberItem) {
     if (this.arrayArrayNumber == null) {
-      this.arrayArrayNumber = new ArrayList<>();
+      this.arrayArrayNumber = ;
     }
     this.arrayArrayNumber.add(arrayArrayNumberItem);
     return this;
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
index 13be31e94a14..d9dac2b82c8a 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -25,7 +25,7 @@ public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
 
   public ArrayOfNumberOnly addArrayNumberItem(BigDecimal arrayNumberItem) {
     if (this.arrayNumber == null) {
-      this.arrayNumber = new ArrayList<>();
+      this.arrayNumber = ;
     }
     this.arrayNumber.add(arrayNumberItem);
     return this;
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayTest.java
index 365022b20af8..04fb30ef274a 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/ArrayTest.java
@@ -31,7 +31,7 @@ public ArrayTest arrayOfString(List<String> arrayOfString) {
 
   public ArrayTest addArrayOfStringItem(String arrayOfStringItem) {
     if (this.arrayOfString == null) {
-      this.arrayOfString = new ArrayList<>();
+      this.arrayOfString = ;
     }
     this.arrayOfString.add(arrayOfStringItem);
     return this;
@@ -57,7 +57,7 @@ public ArrayTest arrayArrayOfInteger(List<List<Long>> arrayArrayOfInteger) {
 
   public ArrayTest addArrayArrayOfIntegerItem(List<Long> arrayArrayOfIntegerItem) {
     if (this.arrayArrayOfInteger == null) {
-      this.arrayArrayOfInteger = new ArrayList<>();
+      this.arrayArrayOfInteger = ;
     }
     this.arrayArrayOfInteger.add(arrayArrayOfIntegerItem);
     return this;
@@ -83,7 +83,7 @@ public ArrayTest arrayArrayOfModel(List<List<@Valid ReadOnlyFirst>> arrayArrayOf
 
   public ArrayTest addArrayArrayOfModelItem(List<@Valid ReadOnlyFirst> arrayArrayOfModelItem) {
     if (this.arrayArrayOfModel == null) {
-      this.arrayArrayOfModel = new ArrayList<>();
+      this.arrayArrayOfModel = ;
     }
     this.arrayArrayOfModel.add(arrayArrayOfModelItem);
     return this;
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumArrays.java
index b249ed882ef3..9c4724b4f779 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/EnumArrays.java
@@ -108,7 +108,7 @@ public EnumArrays arrayEnum(List<ArrayEnumEnum> arrayEnum) {
 
   public EnumArrays addArrayEnumItem(ArrayEnumEnum arrayEnumItem) {
     if (this.arrayEnum == null) {
-      this.arrayEnum = new ArrayList<>();
+      this.arrayEnum = ;
     }
     this.arrayEnum.add(arrayEnumItem);
     return this;
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
index d8709b4fcbac..795f8bd38d67 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/FileSchemaTestClass.java
@@ -46,7 +46,7 @@ public FileSchemaTestClass files(List<@Valid ModelFile> files) {
 
   public FileSchemaTestClass addFilesItem(ModelFile filesItem) {
     if (this.files == null) {
-      this.files = new ArrayList<>();
+      this.files = ;
     }
     this.files.add(filesItem);
     return this;
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Pet.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Pet.java
index ff0f82cbae20..aeda70e5dc4e 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/Pet.java
@@ -156,7 +156,7 @@ public Pet tags(List<@Valid Tag> tags) {
 
   public Pet addTagsItem(Tag tagsItem) {
     if (this.tags == null) {
-      this.tags = new ArrayList<>();
+      this.tags = ;
     }
     this.tags.add(tagsItem);
     return this;
diff --git a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/XmlItem.java
index a009411c58f7..07c6434f21d6 100644
--- a/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/java-msf4j/src/gen/java/org/openapitools/model/XmlItem.java
@@ -181,7 +181,7 @@ public XmlItem wrappedArray(List<Integer> wrappedArray) {
 
   public XmlItem addWrappedArrayItem(Integer wrappedArrayItem) {
     if (this.wrappedArray == null) {
-      this.wrappedArray = new ArrayList<>();
+      this.wrappedArray = ;
     }
     this.wrappedArray.add(wrappedArrayItem);
     return this;
@@ -279,7 +279,7 @@ public XmlItem nameArray(List<Integer> nameArray) {
 
   public XmlItem addNameArrayItem(Integer nameArrayItem) {
     if (this.nameArray == null) {
-      this.nameArray = new ArrayList<>();
+      this.nameArray = ;
     }
     this.nameArray.add(nameArrayItem);
     return this;
@@ -305,7 +305,7 @@ public XmlItem nameWrappedArray(List<Integer> nameWrappedArray) {
 
   public XmlItem addNameWrappedArrayItem(Integer nameWrappedArrayItem) {
     if (this.nameWrappedArray == null) {
-      this.nameWrappedArray = new ArrayList<>();
+      this.nameWrappedArray = ;
     }
     this.nameWrappedArray.add(nameWrappedArrayItem);
     return this;
@@ -403,7 +403,7 @@ public XmlItem prefixArray(List<Integer> prefixArray) {
 
   public XmlItem addPrefixArrayItem(Integer prefixArrayItem) {
     if (this.prefixArray == null) {
-      this.prefixArray = new ArrayList<>();
+      this.prefixArray = ;
     }
     this.prefixArray.add(prefixArrayItem);
     return this;
@@ -429,7 +429,7 @@ public XmlItem prefixWrappedArray(List<Integer> prefixWrappedArray) {
 
   public XmlItem addPrefixWrappedArrayItem(Integer prefixWrappedArrayItem) {
     if (this.prefixWrappedArray == null) {
-      this.prefixWrappedArray = new ArrayList<>();
+      this.prefixWrappedArray = ;
     }
     this.prefixWrappedArray.add(prefixWrappedArrayItem);
     return this;
@@ -527,7 +527,7 @@ public XmlItem namespaceArray(List<Integer> namespaceArray) {
 
   public XmlItem addNamespaceArrayItem(Integer namespaceArrayItem) {
     if (this.namespaceArray == null) {
-      this.namespaceArray = new ArrayList<>();
+      this.namespaceArray = ;
     }
     this.namespaceArray.add(namespaceArrayItem);
     return this;
@@ -553,7 +553,7 @@ public XmlItem namespaceWrappedArray(List<Integer> namespaceWrappedArray) {
 
   public XmlItem addNamespaceWrappedArrayItem(Integer namespaceWrappedArrayItem) {
     if (this.namespaceWrappedArray == null) {
-      this.namespaceWrappedArray = new ArrayList<>();
+      this.namespaceWrappedArray = ;
     }
     this.namespaceWrappedArray.add(namespaceWrappedArrayItem);
     return this;
@@ -651,7 +651,7 @@ public XmlItem prefixNsArray(List<Integer> prefixNsArray) {
 
   public XmlItem addPrefixNsArrayItem(Integer prefixNsArrayItem) {
     if (this.prefixNsArray == null) {
-      this.prefixNsArray = new ArrayList<>();
+      this.prefixNsArray = ;
     }
     this.prefixNsArray.add(prefixNsArrayItem);
     return this;
@@ -677,7 +677,7 @@ public XmlItem prefixNsWrappedArray(List<Integer> prefixNsWrappedArray) {
 
   public XmlItem addPrefixNsWrappedArrayItem(Integer prefixNsWrappedArrayItem) {
     if (this.prefixNsWrappedArray == null) {
-      this.prefixNsWrappedArray = new ArrayList<>();
+      this.prefixNsWrappedArray = ;
     }
     this.prefixNsWrappedArray.add(prefixNsWrappedArrayItem);
     return this;
diff --git a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Pet.java
index 921d2b1bb627..1c9d549266dd 100644
--- a/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/java-undertow/src/main/java/org/openapitools/model/Pet.java
@@ -36,7 +36,7 @@ public class Pet   {
   private Category category;
   private String name;
   private List<String> photoUrls = new ArrayList<>();
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
 
   public enum StatusEnum {
diff --git a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Pet.java b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Pet.java
index 7aae8f77aaad..748f03204861 100644
--- a/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Pet.java
+++ b/samples/server/petstore/java-vertx-web/src/main/java/org/openapitools/vertxweb/server/model/Pet.java
@@ -20,7 +20,7 @@ public class Pet   {
   private Category category;
   private String name;
   private List<String> photoUrls = new ArrayList<>();
-  private List<Tag> tags = new ArrayList<>();
+  private List<Tag> tags;
 
 
   public enum StatusEnum {
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index a3e3f1b10250..ffbb8952dbcc 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7a8a52168934..baa0ed7c0e24 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayTest.java
index b556efec6550..7640fad15268 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/ArrayTest.java
@@ -26,13 +26,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/EnumArrays.java
index efa05bc32eab..0a69fb151098 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/EnumArrays.java
@@ -98,7 +98,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index 0fafd2083e8b..4e0d7f7fa681 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -28,7 +28,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/Pet.java
index f9990b4d4b95..a4cba96ffa00 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/Pet.java
@@ -40,7 +40,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/XmlItem.java
index 8aa00e822f01..f194de7a4e28 100644
--- a/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/spring-boot-defaultInterface-unhandledException/src/main/java/org/openapitools/model/XmlItem.java
@@ -34,7 +34,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -45,10 +45,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -59,10 +59,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -73,10 +73,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -87,10 +87,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/spring-boot-nullable-set/src/main/java/org/openapitools/model/ObjectWithUniqueItems.java b/samples/server/petstore/spring-boot-nullable-set/src/main/java/org/openapitools/model/ObjectWithUniqueItems.java
index 0f9a7f005e79..afa822349738 100644
--- a/samples/server/petstore/spring-boot-nullable-set/src/main/java/org/openapitools/model/ObjectWithUniqueItems.java
+++ b/samples/server/petstore/spring-boot-nullable-set/src/main/java/org/openapitools/model/ObjectWithUniqueItems.java
@@ -35,13 +35,13 @@ public class ObjectWithUniqueItems {
   private JsonNullable<Set<String>> nullSet = JsonNullable.<Set<String>>undefined();
 
   @Valid
-  private Set<String> notNullSet = new LinkedHashSet<>();
+  private Set<String> notNullSet;
 
   @Valid
   private JsonNullable<List<String>> nullList = JsonNullable.<List<String>>undefined();
 
   @Valid
-  private List<String> notNullList = new ArrayList<>();
+  private List<String> notNullList;
 
   @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
   private OffsetDateTime notNullDateField;
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ef7aa874fd3f..bb07dbc9eacf 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index e2779fa9243f..d5e14b4e3674 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayTest.java
index b59c68eb0f2e..251b1852ec8d 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/ArrayTest.java
@@ -26,13 +26,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumArrays.java
index 3f770c79ab5f..7ace2acb940c 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/EnumArrays.java
@@ -98,7 +98,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index aaac9776c8d2..c35a10b1cbbe 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -28,7 +28,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Pet.java
index a4b0607751d5..c66d0008bec2 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/Pet.java
@@ -40,7 +40,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/XmlItem.java
index 39bac753e338..06158c2d1aaf 100644
--- a/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-beanvalidation-no-nullable/src/main/java/org/openapitools/model/XmlItem.java
@@ -34,7 +34,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -45,10 +45,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -59,10 +59,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -73,10 +73,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -87,10 +87,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ef93fc965d29..b3ddf81440c0 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7d17438059ca..72472f324354 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayTest.java
index 33827ecf56c3..1c9ced748f04 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/ArrayTest.java
@@ -27,13 +27,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumArrays.java
index d9ec319c8923..bb318111ab80 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/EnumArrays.java
@@ -99,7 +99,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index f777671acd8a..73f830bf500b 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -29,7 +29,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Pet.java
index 6089ea80e189..52831f69d130 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/Pet.java
@@ -41,7 +41,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/XmlItem.java
index c9ba58e9babb..29a311da4f23 100644
--- a/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-beanvalidation/src/main/java/org/openapitools/model/XmlItem.java
@@ -35,7 +35,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -46,10 +46,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -60,10 +60,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -74,10 +74,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -88,10 +88,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ef93fc965d29..b3ddf81440c0 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7d17438059ca..72472f324354 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayTest.java
index 33827ecf56c3..1c9ced748f04 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/ArrayTest.java
@@ -27,13 +27,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumArrays.java
index d9ec319c8923..bb318111ab80 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/EnumArrays.java
@@ -99,7 +99,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index f777671acd8a..73f830bf500b 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -29,7 +29,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Pet.java
index 6089ea80e189..52831f69d130 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/Pet.java
@@ -41,7 +41,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/XmlItem.java
index c9ba58e9babb..29a311da4f23 100644
--- a/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-delegate-j8/src/main/java/org/openapitools/model/XmlItem.java
@@ -35,7 +35,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -46,10 +46,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -60,10 +60,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -74,10 +74,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -88,10 +88,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Pet.java
index bfd489d624cc..84c1105731f6 100644
--- a/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-delegate-no-response-entity/src/main/java/org/openapitools/model/Pet.java
@@ -39,7 +39,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index 1844fb1521e3..9f53c6754e0e 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly() {
     super();
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index b2426dfb88a6..57dc36e3d5b3 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly() {
     super();
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
index 1dff8f35bacb..bfa7ba7f1d71 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/ArrayTest.java
@@ -27,13 +27,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest() {
     super();
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
index 42017e2946cd..3fecc91475a5 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/EnumArrays.java
@@ -99,7 +99,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays() {
     super();
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index d26fade603d7..31ec127fc3d6 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -29,7 +29,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass() {
     super();
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
index 55823cdd3fbb..f12de2325242 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/Pet.java
@@ -41,7 +41,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
index 45b758015ce9..83bd8025fe7e 100644
--- a/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-delegate/src/main/java/org/openapitools/model/XmlItem.java
@@ -35,7 +35,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -46,10 +46,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -60,10 +60,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -74,10 +74,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -88,10 +88,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem() {
     super();
diff --git a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Pet.java
index 2cfd01b39027..68d8af937ef5 100644
--- a/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-implicitHeaders-annotationLibrary/src/main/java/org/openapitools/model/Pet.java
@@ -36,7 +36,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ef93fc965d29..b3ddf81440c0 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7d17438059ca..72472f324354 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
index 33827ecf56c3..1c9ced748f04 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/ArrayTest.java
@@ -27,13 +27,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
index d9ec319c8923..bb318111ab80 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/EnumArrays.java
@@ -99,7 +99,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index f777671acd8a..73f830bf500b 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -29,7 +29,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
index 6089ea80e189..52831f69d130 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/Pet.java
@@ -41,7 +41,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
index c9ba58e9babb..29a311da4f23 100644
--- a/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-implicitHeaders/src/main/java/org/openapitools/model/XmlItem.java
@@ -35,7 +35,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -46,10 +46,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -60,10 +60,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -74,10 +74,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -88,10 +88,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/springboot-lombok-data/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-lombok-data/src/main/java/org/openapitools/model/Pet.java
index df551276eb7f..db069746d67b 100644
--- a/samples/server/petstore/springboot-lombok-data/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-lombok-data/src/main/java/org/openapitools/model/Pet.java
@@ -42,7 +42,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-lombok-tostring/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-lombok-tostring/src/main/java/org/openapitools/model/Pet.java
index 50247b9006ff..e0afb4d09a71 100644
--- a/samples/server/petstore/springboot-lombok-tostring/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-lombok-tostring/src/main/java/org/openapitools/model/Pet.java
@@ -43,7 +43,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ef93fc965d29..b3ddf81440c0 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7d17438059ca..72472f324354 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java
index 33827ecf56c3..1c9ced748f04 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/ArrayTest.java
@@ -27,13 +27,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java
index d9ec319c8923..bb318111ab80 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/EnumArrays.java
@@ -99,7 +99,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index f777671acd8a..73f830bf500b 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -29,7 +29,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java
index 6089ea80e189..52831f69d130 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/Pet.java
@@ -41,7 +41,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java
index c9ba58e9babb..29a311da4f23 100644
--- a/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-reactive-noResponseEntity/src/main/java/org/openapitools/model/XmlItem.java
@@ -35,7 +35,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -46,10 +46,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -60,10 +60,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -74,10 +74,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -88,10 +88,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ef93fc965d29..b3ddf81440c0 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7d17438059ca..72472f324354 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayTest.java
index 33827ecf56c3..1c9ced748f04 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/ArrayTest.java
@@ -27,13 +27,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumArrays.java
index d9ec319c8923..bb318111ab80 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/EnumArrays.java
@@ -99,7 +99,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index f777671acd8a..73f830bf500b 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -29,7 +29,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Pet.java
index 6089ea80e189..52831f69d130 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/Pet.java
@@ -41,7 +41,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/XmlItem.java
index c9ba58e9babb..29a311da4f23 100644
--- a/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-reactive/src/main/java/org/openapitools/model/XmlItem.java
@@ -35,7 +35,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -46,10 +46,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -60,10 +60,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -74,10 +74,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -88,10 +88,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ef93fc965d29..b3ddf81440c0 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7d17438059ca..72472f324354 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
index 33827ecf56c3..1c9ced748f04 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
@@ -27,13 +27,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
index d9ec319c8923..bb318111ab80 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
@@ -99,7 +99,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index f777671acd8a..73f830bf500b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -29,7 +29,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Pet.java
index f1733c2dfc55..f74c0dec8759 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/XmlItem.java
index c9ba58e9babb..29a311da4f23 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern-without-j8/src/main/java/org/openapitools/model/XmlItem.java
@@ -35,7 +35,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -46,10 +46,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -60,10 +60,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -74,10 +74,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -88,10 +88,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ef93fc965d29..b3ddf81440c0 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7d17438059ca..72472f324354 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayTest.java
index 33827ecf56c3..1c9ced748f04 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/ArrayTest.java
@@ -27,13 +27,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumArrays.java
index d9ec319c8923..bb318111ab80 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/EnumArrays.java
@@ -99,7 +99,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index f777671acd8a..73f830bf500b 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -29,7 +29,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Pet.java
index f1733c2dfc55..f74c0dec8759 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/XmlItem.java
index c9ba58e9babb..29a311da4f23 100644
--- a/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-spring-pageable-delegatePattern/src/main/java/org/openapitools/model/XmlItem.java
@@ -35,7 +35,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -46,10 +46,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -60,10 +60,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -74,10 +74,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -88,10 +88,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ef93fc965d29..b3ddf81440c0 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7d17438059ca..72472f324354 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
index 33827ecf56c3..1c9ced748f04 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/ArrayTest.java
@@ -27,13 +27,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
index d9ec319c8923..bb318111ab80 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/EnumArrays.java
@@ -99,7 +99,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index f777671acd8a..73f830bf500b 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -29,7 +29,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Pet.java
index f1733c2dfc55..f74c0dec8759 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/XmlItem.java
index c9ba58e9babb..29a311da4f23 100644
--- a/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-spring-pageable-without-j8/src/main/java/org/openapitools/model/XmlItem.java
@@ -35,7 +35,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -46,10 +46,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -60,10 +60,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -74,10 +74,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -88,10 +88,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index ef93fc965d29..b3ddf81440c0 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 7d17438059ca..72472f324354 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayTest.java
index 33827ecf56c3..1c9ced748f04 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/ArrayTest.java
@@ -27,13 +27,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumArrays.java
index d9ec319c8923..bb318111ab80 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/EnumArrays.java
@@ -99,7 +99,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index f777671acd8a..73f830bf500b 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -29,7 +29,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Pet.java
index f1733c2dfc55..f74c0dec8759 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/Pet.java
@@ -38,7 +38,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/XmlItem.java
index c9ba58e9babb..29a311da4f23 100644
--- a/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-spring-pageable/src/main/java/org/openapitools/model/XmlItem.java
@@ -35,7 +35,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -46,10 +46,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -60,10 +60,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -74,10 +74,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -88,10 +88,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Pet.java
index e795bdd55ba3..d3be73505fc2 100644
--- a/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-spring-provide-args/src/main/java/org/openapitools/model/Pet.java
@@ -37,7 +37,7 @@ public class Pet {
   private List<String> photoUrls = new ArrayList<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
index d265d3b2937a..ed28ad56d992 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
index 1f7752a075b9..2910dba26894 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayOfNumberOnly.java
@@ -27,7 +27,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayTest.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayTest.java
index de29f0c42304..462d5c1bb49c 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ArrayTest.java
@@ -27,13 +27,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumArrays.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumArrays.java
index b06595b64869..0ffb1bdbbbbb 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumArrays.java
@@ -99,7 +99,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = Optional.of(justSymbol);
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FileSchemaTestClass.java
index a6e078ee88cb..4ec6cdd9e6ac 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FileSchemaTestClass.java
@@ -29,7 +29,7 @@ public class FileSchemaTestClass {
   private Optional<File> file = Optional.empty();
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = Optional.of(file);
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Pet.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Pet.java
index c5f378449dea..89c8e0825a14 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Pet.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Pet.java
@@ -41,7 +41,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/XmlItem.java b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/XmlItem.java
index 43eec94d6ad4..f36326721b3b 100644
--- a/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/XmlItem.java
+++ b/samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/XmlItem.java
@@ -35,7 +35,7 @@ public class XmlItem {
   private Optional<Boolean> attributeBoolean = Optional.empty();
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private Optional<String> nameString = Optional.empty();
 
@@ -46,10 +46,10 @@ public class XmlItem {
   private Optional<Boolean> nameBoolean = Optional.empty();
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private Optional<String> prefixString = Optional.empty();
 
@@ -60,10 +60,10 @@ public class XmlItem {
   private Optional<Boolean> prefixBoolean = Optional.empty();
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private Optional<String> namespaceString = Optional.empty();
 
@@ -74,10 +74,10 @@ public class XmlItem {
   private Optional<Boolean> namespaceBoolean = Optional.empty();
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private Optional<String> prefixNsString = Optional.empty();
 
@@ -88,10 +88,10 @@ public class XmlItem {
   private Optional<Boolean> prefixNsBoolean = Optional.empty();
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = Optional.of(attributeString);
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfArrayOfNumberOnly.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfArrayOfNumberOnly.java
index 6ea77633fc64..8a7986cc11c2 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfArrayOfNumberOnly {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfNumberOnly.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfNumberOnly.java
index 0af18a94ecd0..430e7dea59c6 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfNumberOnly.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayOfNumberOnly.java
@@ -26,7 +26,7 @@
 public class ArrayOfNumberOnly {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayTest.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayTest.java
index 0eff09755404..8470aa3df763 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayTest.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ArrayTest.java
@@ -26,13 +26,13 @@
 public class ArrayTest {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirst>> arrayArrayOfModel;
 
   public ArrayTest arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java
index 9c412ac8635c..4232861ab7cc 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java
@@ -98,7 +98,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FileSchemaTestClass.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FileSchemaTestClass.java
index ef5a8000757f..75d2ca559ab4 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FileSchemaTestClass.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FileSchemaTestClass.java
@@ -28,7 +28,7 @@ public class FileSchemaTestClass {
   private File file;
 
   @Valid
-  private List<@Valid File> files = new ArrayList<>();
+  private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java
index 0526a3dc5e90..b07a0e0a0669 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java
@@ -40,7 +40,7 @@ public class Pet {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid Tag> tags = new ArrayList<>();
+  private List<@Valid Tag> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/XmlItem.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/XmlItem.java
index 99edb8648e74..33f310e35c0c 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/XmlItem.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/XmlItem.java
@@ -34,7 +34,7 @@ public class XmlItem {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -45,10 +45,10 @@ public class XmlItem {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -59,10 +59,10 @@ public class XmlItem {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -73,10 +73,10 @@ public class XmlItem {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -87,10 +87,10 @@ public class XmlItem {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
     this.attributeString = attributeString;
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
index d3147f8cdd1d..b781fe83ac25 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfArrayOfNumberOnlyDto.java
@@ -29,7 +29,7 @@
 public class ArrayOfArrayOfNumberOnlyDto {
 
   @Valid
-  private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
+  private List<List<BigDecimal>> arrayArrayNumber;
 
   public ArrayOfArrayOfNumberOnlyDto arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
index 9eade3bbdb3d..a6890bd49a38 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayOfNumberOnlyDto.java
@@ -29,7 +29,7 @@
 public class ArrayOfNumberOnlyDto {
 
   @Valid
-  private List<BigDecimal> arrayNumber = new ArrayList<>();
+  private List<BigDecimal> arrayNumber;
 
   public ArrayOfNumberOnlyDto arrayNumber(List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayTestDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayTestDto.java
index a04d3d5a1e97..a566b7b993d5 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayTestDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/ArrayTestDto.java
@@ -29,13 +29,13 @@
 public class ArrayTestDto {
 
   @Valid
-  private List<String> arrayOfString = new ArrayList<>();
+  private List<String> arrayOfString;
 
   @Valid
-  private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
+  private List<List<Long>> arrayArrayOfInteger;
 
   @Valid
-  private List<List<@Valid ReadOnlyFirstDto>> arrayArrayOfModel = new ArrayList<>();
+  private List<List<@Valid ReadOnlyFirstDto>> arrayArrayOfModel;
 
   public ArrayTestDto arrayOfString(List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumArraysDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumArraysDto.java
index 678350cd3f88..f058e6ac9dbc 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumArraysDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/EnumArraysDto.java
@@ -101,7 +101,7 @@ public static ArrayEnumEnum fromValue(String value) {
   }
 
   @Valid
-  private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
+  private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArraysDto justSymbol(JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
index ef4436979948..ccfe32823c48 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/FileSchemaTestClassDto.java
@@ -31,7 +31,7 @@ public class FileSchemaTestClassDto {
   private FileDto file;
 
   @Valid
-  private List<@Valid FileDto> files = new ArrayList<>();
+  private List<@Valid FileDto> files;
 
   public FileSchemaTestClassDto file(FileDto file) {
     this.file = file;
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/PetDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/PetDto.java
index a86fa9d7ff00..52ce980ff260 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/PetDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/PetDto.java
@@ -43,7 +43,7 @@ public class PetDto {
   private Set<String> photoUrls = new LinkedHashSet<>();
 
   @Valid
-  private List<@Valid TagDto> tags = new ArrayList<>();
+  private List<@Valid TagDto> tags;
 
   /**
    * pet status in the store
diff --git a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/XmlItemDto.java b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/XmlItemDto.java
index 013e6014ed5d..cc0996569627 100644
--- a/samples/server/petstore/springboot/src/main/java/org/openapitools/model/XmlItemDto.java
+++ b/samples/server/petstore/springboot/src/main/java/org/openapitools/model/XmlItemDto.java
@@ -37,7 +37,7 @@ public class XmlItemDto {
   private Boolean attributeBoolean;
 
   @Valid
-  private List<Integer> wrappedArray = new ArrayList<>();
+  private List<Integer> wrappedArray;
 
   private String nameString;
 
@@ -48,10 +48,10 @@ public class XmlItemDto {
   private Boolean nameBoolean;
 
   @Valid
-  private List<Integer> nameArray = new ArrayList<>();
+  private List<Integer> nameArray;
 
   @Valid
-  private List<Integer> nameWrappedArray = new ArrayList<>();
+  private List<Integer> nameWrappedArray;
 
   private String prefixString;
 
@@ -62,10 +62,10 @@ public class XmlItemDto {
   private Boolean prefixBoolean;
 
   @Valid
-  private List<Integer> prefixArray = new ArrayList<>();
+  private List<Integer> prefixArray;
 
   @Valid
-  private List<Integer> prefixWrappedArray = new ArrayList<>();
+  private List<Integer> prefixWrappedArray;
 
   private String namespaceString;
 
@@ -76,10 +76,10 @@ public class XmlItemDto {
   private Boolean namespaceBoolean;
 
   @Valid
-  private List<Integer> namespaceArray = new ArrayList<>();
+  private List<Integer> namespaceArray;
 
   @Valid
-  private List<Integer> namespaceWrappedArray = new ArrayList<>();
+  private List<Integer> namespaceWrappedArray;
 
   private String prefixNsString;
 
@@ -90,10 +90,10 @@ public class XmlItemDto {
   private Boolean prefixNsBoolean;
 
   @Valid
-  private List<Integer> prefixNsArray = new ArrayList<>();
+  private List<Integer> prefixNsArray;
 
   @Valid
-  private List<Integer> prefixNsWrappedArray = new ArrayList<>();
+  private List<Integer> prefixNsWrappedArray;
 
   public XmlItemDto attributeString(String attributeString) {
     this.attributeString = attributeString;