diff --git a/diktat-rules/src/main/kotlin/generated/WarningNames.kt b/diktat-rules/src/main/kotlin/generated/WarningNames.kt
index 4e75adb157..e8043f0aee 100644
--- a/diktat-rules/src/main/kotlin/generated/WarningNames.kt
+++ b/diktat-rules/src/main/kotlin/generated/WarningNames.kt
@@ -121,6 +121,8 @@ public object WarningNames {
 
     public const val FILE_WILDCARD_IMPORTS: String = "FILE_WILDCARD_IMPORTS"
 
+    public const val UNUSED_IMPORT: String = "UNUSED_IMPORT"
+
     public const val NO_BRACES_IN_CONDITIONALS_AND_LOOPS: String =
             "NO_BRACES_IN_CONDITIONALS_AND_LOOPS"
 
@@ -203,8 +205,12 @@ public object WarningNames {
 
     public const val RUN_BLOCKING_INSIDE_ASYNC: String = "RUN_BLOCKING_INSIDE_ASYNC"
 
+    public const val TOO_MANY_LINES_IN_LAMBDA: String = "TOO_MANY_LINES_IN_LAMBDA"
+
     public const val CUSTOM_LABEL: String = "CUSTOM_LABEL"
 
+    public const val INVERSE_FUNCTION_PREFERRED: String = "INVERSE_FUNCTION_PREFERRED"
+
     public const val SINGLE_CONSTRUCTOR_SHOULD_BE_PRIMARY: String =
             "SINGLE_CONSTRUCTOR_SHOULD_BE_PRIMARY"
 
@@ -236,12 +242,6 @@ public object WarningNames {
 
     public const val OBJECT_IS_PREFERRED: String = "OBJECT_IS_PREFERRED"
 
-    public const val INVERSE_FUNCTION_PREFERRED: String = "INVERSE_FUNCTION_PREFERRED"
-
-    public const val TOO_MANY_LINES_IN_LAMBDA: String = "TOO_MANY_LINES_IN_LAMBDA"
-
-    public const val UNUSED_IMPORT: String = "UNUSED_IMPORT"
-
     public const val INLINE_CLASS_CAN_BE_USED: String = "INLINE_CLASS_CAN_BE_USED"
 
     public const val EXTENSION_FUNCTION_WITH_CLASS: String = "EXTENSION_FUNCTION_WITH_CLASS"
diff --git a/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/chapter6/ExtensionFunctionsInFileRule.kt b/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/chapter6/ExtensionFunctionsInFileRule.kt
index 74a7b71032..4c627e3166 100644
--- a/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/chapter6/ExtensionFunctionsInFileRule.kt
+++ b/diktat-rules/src/main/kotlin/org/cqfn/diktat/ruleset/rules/chapter6/ExtensionFunctionsInFileRule.kt
@@ -4,18 +4,16 @@ import org.cqfn.diktat.common.config.rules.RulesConfig
 import org.cqfn.diktat.ruleset.constants.EmitType
 import org.cqfn.diktat.ruleset.constants.Warnings
 import org.cqfn.diktat.ruleset.utils.findAllNodesWithSpecificType
+import org.cqfn.diktat.ruleset.utils.getAllChildrenWithType
 import org.cqfn.diktat.ruleset.utils.getFirstChildWithType
-import org.cqfn.diktat.ruleset.utils.hasChildOfType
 
 import com.pinterest.ktlint.core.Rule
 import com.pinterest.ktlint.core.ast.ElementType
 import com.pinterest.ktlint.core.ast.ElementType.CLASS
-import com.pinterest.ktlint.core.ast.ElementType.DOT
 import com.pinterest.ktlint.core.ast.ElementType.FUN
 import com.pinterest.ktlint.core.ast.ElementType.IDENTIFIER
 import com.pinterest.ktlint.core.ast.ElementType.TYPE_REFERENCE
 import com.pinterest.ktlint.core.ast.prevSibling
-import org.cqfn.diktat.ruleset.utils.getAllChildrenWithType
 import org.jetbrains.kotlin.com.intellij.lang.ASTNode
 import org.jetbrains.kotlin.psi.KtClass
 import org.jetbrains.kotlin.psi.KtFunction
@@ -53,13 +51,11 @@ class ExtensionFunctionsInFileRule(private val configRules: List<RulesConfig>) :
         Warnings.EXTENSION_FUNCTION_WITH_CLASS.warn(configRules, emitWarn, isFixMode, "fun ${(node.psi as KtFunction).name}", node.startOffset, node)
     }
 
-    private fun collectAllExtensionFunctionsWithSameClassName(node: ASTNode, classNames: List<String>): List<ASTNode> {
-        return node.getAllChildrenWithType(FUN).filter { isExtensionFunctionWithClassName(it, classNames) }
-    }
+    private fun collectAllExtensionFunctionsWithSameClassName(node: ASTNode, classNames: List<String>): List<ASTNode> =
+            node.getAllChildrenWithType(FUN).filter { isExtensionFunctionWithClassName(it, classNames) }
+
 
     @Suppress("UnsafeCallOnNullableType")
     private fun isExtensionFunctionWithClassName(node: ASTNode, classNames: List<String>): Boolean =
-         node.getFirstChildWithType(IDENTIFIER)!!.prevSibling { it.elementType == TYPE_REFERENCE } != null
-             && node.getFirstChildWithType(IDENTIFIER)!!.prevSibling { it.elementType == TYPE_REFERENCE }!!.text in classNames
-
+            node.getFirstChildWithType(IDENTIFIER)!!.prevSibling { it.elementType == TYPE_REFERENCE }?.text in classNames
 }