diff --git a/java-workflows/README.md b/java-workflows/README.md
index 4900156490b7..410f7c26fd67 100644
--- a/java-workflows/README.md
+++ b/java-workflows/README.md
@@ -27,13 +27,13 @@ If you are using Maven, add this to your pom.xml file:
 If you are using Gradle without BOM, add this to your dependencies:
 
 ```Groovy
-implementation 'com.google.cloud:google-cloud-workflows:2.3.4'
+implementation 'com.google.cloud:google-cloud-workflows:2.3.5'
 ```
 
 If you are using SBT, add this to your dependencies:
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-workflows" % "2.3.4"
+libraryDependencies += "com.google.cloud" % "google-cloud-workflows" % "2.3.5"
 ```
 
 ## Authentication
diff --git a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/CreateWorkflowRequest.java b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/CreateWorkflowRequest.java
index b4b52d22b0d3..c567c58cc9b8 100644
--- a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/CreateWorkflowRequest.java
+++ b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/CreateWorkflowRequest.java
@@ -55,75 +55,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private CreateWorkflowRequest(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              parent_ = s;
-              break;
-            }
-          case 18:
-            {
-              com.google.cloud.workflows.v1.Workflow.Builder subBuilder = null;
-              if (workflow_ != null) {
-                subBuilder = workflow_.toBuilder();
-              }
-              workflow_ =
-                  input.readMessage(
-                      com.google.cloud.workflows.v1.Workflow.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(workflow_);
-                workflow_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 26:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              workflowId_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1.WorkflowsProto
         .internal_static_google_cloud_workflows_v1_CreateWorkflowRequest_descriptor;
@@ -332,7 +263,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(workflowId_)) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 3, workflowId_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -350,7 +281,7 @@ public int getSerializedSize() {
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(workflowId_)) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(3, workflowId_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -372,7 +303,7 @@ public boolean equals(final java.lang.Object obj) {
       if (!getWorkflow().equals(other.getWorkflow())) return false;
     }
     if (!getWorkflowId().equals(other.getWorkflowId())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -391,7 +322,7 @@ public int hashCode() {
     }
     hash = (37 * hash) + WORKFLOW_ID_FIELD_NUMBER;
     hash = (53 * hash) + getWorkflowId().hashCode();
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -522,17 +453,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1.CreateWorkflowRequest.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -643,7 +567,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1.CreateWorkflowRequest oth
         workflowId_ = other.workflowId_;
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -658,18 +582,49 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1.CreateWorkflowRequest parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                parent_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 10
+            case 18:
+              {
+                input.readMessage(getWorkflowFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 18
+            case 26:
+              {
+                workflowId_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 26
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1.CreateWorkflowRequest) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -1165,7 +1120,18 @@ public CreateWorkflowRequest parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new CreateWorkflowRequest(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/DeleteWorkflowRequest.java b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/DeleteWorkflowRequest.java
index 9956217ef625..28043b09e325 100644
--- a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/DeleteWorkflowRequest.java
+++ b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/DeleteWorkflowRequest.java
@@ -54,52 +54,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private DeleteWorkflowRequest(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              name_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1.WorkflowsProto
         .internal_static_google_cloud_workflows_v1_DeleteWorkflowRequest_descriptor;
@@ -187,7 +141,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(name_)) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 1, name_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -199,7 +153,7 @@ public int getSerializedSize() {
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(name_)) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(1, name_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -216,7 +170,7 @@ public boolean equals(final java.lang.Object obj) {
         (com.google.cloud.workflows.v1.DeleteWorkflowRequest) obj;
 
     if (!getName().equals(other.getName())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -229,7 +183,7 @@ public int hashCode() {
     hash = (19 * hash) + getDescriptor().hashCode();
     hash = (37 * hash) + NAME_FIELD_NUMBER;
     hash = (53 * hash) + getName().hashCode();
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -360,17 +314,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1.DeleteWorkflowRequest.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -460,7 +407,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1.DeleteWorkflowRequest oth
         name_ = other.name_;
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -475,18 +422,37 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1.DeleteWorkflowRequest parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                name_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 10
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1.DeleteWorkflowRequest) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -643,7 +609,18 @@ public DeleteWorkflowRequest parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new DeleteWorkflowRequest(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/GetWorkflowRequest.java b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/GetWorkflowRequest.java
index b0845a35afc1..515ca33a6c63 100644
--- a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/GetWorkflowRequest.java
+++ b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/GetWorkflowRequest.java
@@ -53,52 +53,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private GetWorkflowRequest(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              name_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1.WorkflowsProto
         .internal_static_google_cloud_workflows_v1_GetWorkflowRequest_descriptor;
@@ -186,7 +140,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(name_)) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 1, name_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -198,7 +152,7 @@ public int getSerializedSize() {
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(name_)) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(1, name_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -215,7 +169,7 @@ public boolean equals(final java.lang.Object obj) {
         (com.google.cloud.workflows.v1.GetWorkflowRequest) obj;
 
     if (!getName().equals(other.getName())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -228,7 +182,7 @@ public int hashCode() {
     hash = (19 * hash) + getDescriptor().hashCode();
     hash = (37 * hash) + NAME_FIELD_NUMBER;
     hash = (53 * hash) + getName().hashCode();
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -358,17 +312,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1.GetWorkflowRequest.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -458,7 +405,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1.GetWorkflowRequest other)
         name_ = other.name_;
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -473,17 +420,37 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1.GetWorkflowRequest parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                name_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 10
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage = (com.google.cloud.workflows.v1.GetWorkflowRequest) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -640,7 +607,18 @@ public GetWorkflowRequest parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new GetWorkflowRequest(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/ListWorkflowsRequest.java b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/ListWorkflowsRequest.java
index f51010c6af3b..b21e734152cb 100644
--- a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/ListWorkflowsRequest.java
+++ b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/ListWorkflowsRequest.java
@@ -57,78 +57,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private ListWorkflowsRequest(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              parent_ = s;
-              break;
-            }
-          case 16:
-            {
-              pageSize_ = input.readInt32();
-              break;
-            }
-          case 26:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              pageToken_ = s;
-              break;
-            }
-          case 34:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              filter_ = s;
-              break;
-            }
-          case 42:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              orderBy_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1.WorkflowsProto
         .internal_static_google_cloud_workflows_v1_ListWorkflowsRequest_descriptor;
@@ -408,7 +336,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(orderBy_)) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 5, orderBy_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -432,7 +360,7 @@ public int getSerializedSize() {
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(orderBy_)) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(5, orderBy_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -453,7 +381,7 @@ public boolean equals(final java.lang.Object obj) {
     if (!getPageToken().equals(other.getPageToken())) return false;
     if (!getFilter().equals(other.getFilter())) return false;
     if (!getOrderBy().equals(other.getOrderBy())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -474,7 +402,7 @@ public int hashCode() {
     hash = (53 * hash) + getFilter().hashCode();
     hash = (37 * hash) + ORDER_BY_FIELD_NUMBER;
     hash = (53 * hash) + getOrderBy().hashCode();
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -605,17 +533,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1.ListWorkflowsRequest.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -732,7 +653,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1.ListWorkflowsRequest othe
         orderBy_ = other.orderBy_;
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -747,18 +668,61 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1.ListWorkflowsRequest parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                parent_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 10
+            case 16:
+              {
+                pageSize_ = input.readInt32();
+
+                break;
+              } // case 16
+            case 26:
+              {
+                pageToken_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 26
+            case 34:
+              {
+                filter_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 34
+            case 42:
+              {
+                orderBy_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 42
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1.ListWorkflowsRequest) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -1324,7 +1288,18 @@ public ListWorkflowsRequest parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new ListWorkflowsRequest(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/ListWorkflowsResponse.java b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/ListWorkflowsResponse.java
index a806d2525155..572674d2d191 100644
--- a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/ListWorkflowsResponse.java
+++ b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/ListWorkflowsResponse.java
@@ -56,80 +56,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private ListWorkflowsResponse(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    int mutable_bitField0_ = 0;
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              if (!((mutable_bitField0_ & 0x00000001) != 0)) {
-                workflows_ = new java.util.ArrayList<com.google.cloud.workflows.v1.Workflow>();
-                mutable_bitField0_ |= 0x00000001;
-              }
-              workflows_.add(
-                  input.readMessage(
-                      com.google.cloud.workflows.v1.Workflow.parser(), extensionRegistry));
-              break;
-            }
-          case 18:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              nextPageToken_ = s;
-              break;
-            }
-          case 26:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-              if (!((mutable_bitField0_ & 0x00000002) != 0)) {
-                unreachable_ = new com.google.protobuf.LazyStringArrayList();
-                mutable_bitField0_ |= 0x00000002;
-              }
-              unreachable_.add(s);
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      if (((mutable_bitField0_ & 0x00000001) != 0)) {
-        workflows_ = java.util.Collections.unmodifiableList(workflows_);
-      }
-      if (((mutable_bitField0_ & 0x00000002) != 0)) {
-        unreachable_ = unreachable_.getUnmodifiableView();
-      }
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1.WorkflowsProto
         .internal_static_google_cloud_workflows_v1_ListWorkflowsResponse_descriptor;
@@ -349,7 +275,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     for (int i = 0; i < unreachable_.size(); i++) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 3, unreachable_.getRaw(i));
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -372,7 +298,7 @@ public int getSerializedSize() {
       size += dataSize;
       size += 1 * getUnreachableList().size();
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -391,7 +317,7 @@ public boolean equals(final java.lang.Object obj) {
     if (!getWorkflowsList().equals(other.getWorkflowsList())) return false;
     if (!getNextPageToken().equals(other.getNextPageToken())) return false;
     if (!getUnreachableList().equals(other.getUnreachableList())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -412,7 +338,7 @@ public int hashCode() {
       hash = (37 * hash) + UNREACHABLE_FIELD_NUMBER;
       hash = (53 * hash) + getUnreachableList().hashCode();
     }
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -543,19 +469,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1.ListWorkflowsResponse.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {
-        getWorkflowsFieldBuilder();
-      }
     }
 
     @java.lang.Override
@@ -563,10 +480,11 @@ public Builder clear() {
       super.clear();
       if (workflowsBuilder_ == null) {
         workflows_ = java.util.Collections.emptyList();
-        bitField0_ = (bitField0_ & ~0x00000001);
       } else {
+        workflows_ = null;
         workflowsBuilder_.clear();
       }
+      bitField0_ = (bitField0_ & ~0x00000001);
       nextPageToken_ = "";
 
       unreachable_ = com.google.protobuf.LazyStringArrayList.EMPTY;
@@ -705,7 +623,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1.ListWorkflowsResponse oth
         }
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -720,18 +638,57 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1.ListWorkflowsResponse parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                com.google.cloud.workflows.v1.Workflow m =
+                    input.readMessage(
+                        com.google.cloud.workflows.v1.Workflow.parser(), extensionRegistry);
+                if (workflowsBuilder_ == null) {
+                  ensureWorkflowsIsMutable();
+                  workflows_.add(m);
+                } else {
+                  workflowsBuilder_.addMessage(m);
+                }
+                break;
+              } // case 10
+            case 18:
+              {
+                nextPageToken_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 18
+            case 26:
+              {
+                java.lang.String s = input.readStringRequireUtf8();
+                ensureUnreachableIsMutable();
+                unreachable_.add(s);
+                break;
+              } // case 26
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1.ListWorkflowsResponse) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -1397,7 +1354,18 @@ public ListWorkflowsResponse parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new ListWorkflowsResponse(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/OperationMetadata.java b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/OperationMetadata.java
index 1fc44d0be65d..35a3f16bfc34 100644
--- a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/OperationMetadata.java
+++ b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/OperationMetadata.java
@@ -54,96 +54,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private OperationMetadata(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              com.google.protobuf.Timestamp.Builder subBuilder = null;
-              if (createTime_ != null) {
-                subBuilder = createTime_.toBuilder();
-              }
-              createTime_ =
-                  input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(createTime_);
-                createTime_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 18:
-            {
-              com.google.protobuf.Timestamp.Builder subBuilder = null;
-              if (endTime_ != null) {
-                subBuilder = endTime_.toBuilder();
-              }
-              endTime_ =
-                  input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(endTime_);
-                endTime_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 26:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              target_ = s;
-              break;
-            }
-          case 34:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              verb_ = s;
-              break;
-            }
-          case 42:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              apiVersion_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1.WorkflowsProto
         .internal_static_google_cloud_workflows_v1_OperationMetadata_descriptor;
@@ -427,7 +337,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(apiVersion_)) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 5, apiVersion_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -451,7 +361,7 @@ public int getSerializedSize() {
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(apiVersion_)) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(5, apiVersion_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -478,7 +388,7 @@ public boolean equals(final java.lang.Object obj) {
     if (!getTarget().equals(other.getTarget())) return false;
     if (!getVerb().equals(other.getVerb())) return false;
     if (!getApiVersion().equals(other.getApiVersion())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -503,7 +413,7 @@ public int hashCode() {
     hash = (53 * hash) + getVerb().hashCode();
     hash = (37 * hash) + API_VERSION_FIELD_NUMBER;
     hash = (53 * hash) + getApiVersion().hashCode();
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -632,17 +542,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1.OperationMetadata.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -774,7 +677,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1.OperationMetadata other)
         apiVersion_ = other.apiVersion_;
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -789,17 +692,61 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1.OperationMetadata parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                input.readMessage(getCreateTimeFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 10
+            case 18:
+              {
+                input.readMessage(getEndTimeFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 18
+            case 26:
+              {
+                target_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 26
+            case 34:
+              {
+                verb_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 34
+            case 42:
+              {
+                apiVersion_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 42
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage = (com.google.cloud.workflows.v1.OperationMetadata) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -1515,7 +1462,18 @@ public OperationMetadata parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new OperationMetadata(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/UpdateWorkflowRequest.java b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/UpdateWorkflowRequest.java
index dd8e99af332b..f28257ffc802 100644
--- a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/UpdateWorkflowRequest.java
+++ b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/UpdateWorkflowRequest.java
@@ -52,76 +52,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private UpdateWorkflowRequest(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              com.google.cloud.workflows.v1.Workflow.Builder subBuilder = null;
-              if (workflow_ != null) {
-                subBuilder = workflow_.toBuilder();
-              }
-              workflow_ =
-                  input.readMessage(
-                      com.google.cloud.workflows.v1.Workflow.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(workflow_);
-                workflow_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 18:
-            {
-              com.google.protobuf.FieldMask.Builder subBuilder = null;
-              if (updateMask_ != null) {
-                subBuilder = updateMask_.toBuilder();
-              }
-              updateMask_ =
-                  input.readMessage(com.google.protobuf.FieldMask.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(updateMask_);
-                updateMask_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1.WorkflowsProto
         .internal_static_google_cloud_workflows_v1_UpdateWorkflowRequest_descriptor;
@@ -260,7 +190,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (updateMask_ != null) {
       output.writeMessage(2, getUpdateMask());
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -275,7 +205,7 @@ public int getSerializedSize() {
     if (updateMask_ != null) {
       size += com.google.protobuf.CodedOutputStream.computeMessageSize(2, getUpdateMask());
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -299,7 +229,7 @@ public boolean equals(final java.lang.Object obj) {
     if (hasUpdateMask()) {
       if (!getUpdateMask().equals(other.getUpdateMask())) return false;
     }
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -318,7 +248,7 @@ public int hashCode() {
       hash = (37 * hash) + UPDATE_MASK_FIELD_NUMBER;
       hash = (53 * hash) + getUpdateMask().hashCode();
     }
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -449,17 +379,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1.UpdateWorkflowRequest.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -570,7 +493,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1.UpdateWorkflowRequest oth
       if (other.hasUpdateMask()) {
         mergeUpdateMask(other.getUpdateMask());
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -585,18 +508,43 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1.UpdateWorkflowRequest parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                input.readMessage(getWorkflowFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 10
+            case 18:
+              {
+                input.readMessage(getUpdateMaskFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 18
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1.UpdateWorkflowRequest) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -1027,7 +975,18 @@ public UpdateWorkflowRequest parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new UpdateWorkflowRequest(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/Workflow.java b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/Workflow.java
index 6d4d23a4756d..b4837f6fd498 100644
--- a/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/Workflow.java
+++ b/java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/Workflow.java
@@ -56,146 +56,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private Workflow(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    int mutable_bitField0_ = 0;
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              name_ = s;
-              break;
-            }
-          case 18:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              description_ = s;
-              break;
-            }
-          case 24:
-            {
-              int rawValue = input.readEnum();
-
-              state_ = rawValue;
-              break;
-            }
-          case 34:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              revisionId_ = s;
-              break;
-            }
-          case 42:
-            {
-              com.google.protobuf.Timestamp.Builder subBuilder = null;
-              if (createTime_ != null) {
-                subBuilder = createTime_.toBuilder();
-              }
-              createTime_ =
-                  input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(createTime_);
-                createTime_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 50:
-            {
-              com.google.protobuf.Timestamp.Builder subBuilder = null;
-              if (updateTime_ != null) {
-                subBuilder = updateTime_.toBuilder();
-              }
-              updateTime_ =
-                  input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(updateTime_);
-                updateTime_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 58:
-            {
-              com.google.protobuf.Timestamp.Builder subBuilder = null;
-              if (revisionCreateTime_ != null) {
-                subBuilder = revisionCreateTime_.toBuilder();
-              }
-              revisionCreateTime_ =
-                  input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(revisionCreateTime_);
-                revisionCreateTime_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 66:
-            {
-              if (!((mutable_bitField0_ & 0x00000001) != 0)) {
-                labels_ =
-                    com.google.protobuf.MapField.newMapField(LabelsDefaultEntryHolder.defaultEntry);
-                mutable_bitField0_ |= 0x00000001;
-              }
-              com.google.protobuf.MapEntry<java.lang.String, java.lang.String> labels__ =
-                  input.readMessage(
-                      LabelsDefaultEntryHolder.defaultEntry.getParserForType(), extensionRegistry);
-              labels_.getMutableMap().put(labels__.getKey(), labels__.getValue());
-              break;
-            }
-          case 74:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              serviceAccount_ = s;
-              break;
-            }
-          case 82:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-              sourceCodeCase_ = 10;
-              sourceCode_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1.WorkflowsProto
         .internal_static_google_cloud_workflows_v1_Workflow_descriptor;
@@ -1056,7 +916,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (sourceCodeCase_ == 10) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 10, sourceCode_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -1102,7 +962,7 @@ public int getSerializedSize() {
     if (sourceCodeCase_ == 10) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(10, sourceCode_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -1143,7 +1003,7 @@ public boolean equals(final java.lang.Object obj) {
       case 0:
       default:
     }
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -1188,7 +1048,7 @@ public int hashCode() {
       case 0:
       default:
     }
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -1337,17 +1197,10 @@ protected com.google.protobuf.MapField internalGetMutableMapField(int number) {
     }
 
     // Construct using com.google.cloud.workflows.v1.Workflow.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -1529,7 +1382,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1.Workflow other) {
             break;
           }
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -1544,17 +1397,98 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1.Workflow parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                name_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 10
+            case 18:
+              {
+                description_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 18
+            case 24:
+              {
+                state_ = input.readEnum();
+
+                break;
+              } // case 24
+            case 34:
+              {
+                revisionId_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 34
+            case 42:
+              {
+                input.readMessage(getCreateTimeFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 42
+            case 50:
+              {
+                input.readMessage(getUpdateTimeFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 50
+            case 58:
+              {
+                input.readMessage(
+                    getRevisionCreateTimeFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 58
+            case 66:
+              {
+                com.google.protobuf.MapEntry<java.lang.String, java.lang.String> labels__ =
+                    input.readMessage(
+                        LabelsDefaultEntryHolder.defaultEntry.getParserForType(),
+                        extensionRegistry);
+                internalGetMutableLabels()
+                    .getMutableMap()
+                    .put(labels__.getKey(), labels__.getValue());
+                break;
+              } // case 66
+            case 74:
+              {
+                serviceAccount_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 74
+            case 82:
+              {
+                java.lang.String s = input.readStringRequireUtf8();
+                sourceCodeCase_ = 10;
+                sourceCode_ = s;
+                break;
+              } // case 82
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage = (com.google.cloud.workflows.v1.Workflow) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -3155,7 +3089,18 @@ public Workflow parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new Workflow(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/CreateWorkflowRequest.java b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/CreateWorkflowRequest.java
index e6e502e7b262..3b59c84385fa 100644
--- a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/CreateWorkflowRequest.java
+++ b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/CreateWorkflowRequest.java
@@ -55,75 +55,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private CreateWorkflowRequest(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              parent_ = s;
-              break;
-            }
-          case 18:
-            {
-              com.google.cloud.workflows.v1beta.Workflow.Builder subBuilder = null;
-              if (workflow_ != null) {
-                subBuilder = workflow_.toBuilder();
-              }
-              workflow_ =
-                  input.readMessage(
-                      com.google.cloud.workflows.v1beta.Workflow.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(workflow_);
-                workflow_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 26:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              workflowId_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1beta.WorkflowsProto
         .internal_static_google_cloud_workflows_v1beta_CreateWorkflowRequest_descriptor;
@@ -332,7 +263,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(workflowId_)) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 3, workflowId_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -350,7 +281,7 @@ public int getSerializedSize() {
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(workflowId_)) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(3, workflowId_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -372,7 +303,7 @@ public boolean equals(final java.lang.Object obj) {
       if (!getWorkflow().equals(other.getWorkflow())) return false;
     }
     if (!getWorkflowId().equals(other.getWorkflowId())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -391,7 +322,7 @@ public int hashCode() {
     }
     hash = (37 * hash) + WORKFLOW_ID_FIELD_NUMBER;
     hash = (53 * hash) + getWorkflowId().hashCode();
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -523,17 +454,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1beta.CreateWorkflowRequest.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -644,7 +568,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1beta.CreateWorkflowRequest
         workflowId_ = other.workflowId_;
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -659,18 +583,49 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1beta.CreateWorkflowRequest parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                parent_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 10
+            case 18:
+              {
+                input.readMessage(getWorkflowFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 18
+            case 26:
+              {
+                workflowId_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 26
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1beta.CreateWorkflowRequest) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -1166,7 +1121,18 @@ public CreateWorkflowRequest parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new CreateWorkflowRequest(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/DeleteWorkflowRequest.java b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/DeleteWorkflowRequest.java
index 05ca936ee147..a44f0d9b4cb6 100644
--- a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/DeleteWorkflowRequest.java
+++ b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/DeleteWorkflowRequest.java
@@ -54,52 +54,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private DeleteWorkflowRequest(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              name_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1beta.WorkflowsProto
         .internal_static_google_cloud_workflows_v1beta_DeleteWorkflowRequest_descriptor;
@@ -187,7 +141,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(name_)) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 1, name_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -199,7 +153,7 @@ public int getSerializedSize() {
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(name_)) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(1, name_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -216,7 +170,7 @@ public boolean equals(final java.lang.Object obj) {
         (com.google.cloud.workflows.v1beta.DeleteWorkflowRequest) obj;
 
     if (!getName().equals(other.getName())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -229,7 +183,7 @@ public int hashCode() {
     hash = (19 * hash) + getDescriptor().hashCode();
     hash = (37 * hash) + NAME_FIELD_NUMBER;
     hash = (53 * hash) + getName().hashCode();
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -361,17 +315,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1beta.DeleteWorkflowRequest.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -461,7 +408,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1beta.DeleteWorkflowRequest
         name_ = other.name_;
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -476,18 +423,37 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1beta.DeleteWorkflowRequest parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                name_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 10
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1beta.DeleteWorkflowRequest) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -644,7 +610,18 @@ public DeleteWorkflowRequest parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new DeleteWorkflowRequest(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/GetWorkflowRequest.java b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/GetWorkflowRequest.java
index 849ded9c21c9..98d8121335ae 100644
--- a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/GetWorkflowRequest.java
+++ b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/GetWorkflowRequest.java
@@ -53,52 +53,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private GetWorkflowRequest(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              name_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1beta.WorkflowsProto
         .internal_static_google_cloud_workflows_v1beta_GetWorkflowRequest_descriptor;
@@ -186,7 +140,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(name_)) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 1, name_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -198,7 +152,7 @@ public int getSerializedSize() {
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(name_)) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(1, name_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -215,7 +169,7 @@ public boolean equals(final java.lang.Object obj) {
         (com.google.cloud.workflows.v1beta.GetWorkflowRequest) obj;
 
     if (!getName().equals(other.getName())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -228,7 +182,7 @@ public int hashCode() {
     hash = (19 * hash) + getDescriptor().hashCode();
     hash = (37 * hash) + NAME_FIELD_NUMBER;
     hash = (53 * hash) + getName().hashCode();
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -358,17 +312,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1beta.GetWorkflowRequest.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -458,7 +405,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1beta.GetWorkflowRequest ot
         name_ = other.name_;
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -473,18 +420,37 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1beta.GetWorkflowRequest parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                name_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 10
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1beta.GetWorkflowRequest) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -641,7 +607,18 @@ public GetWorkflowRequest parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new GetWorkflowRequest(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/ListWorkflowsRequest.java b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/ListWorkflowsRequest.java
index f6724a77bc8f..9f7b21440fdd 100644
--- a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/ListWorkflowsRequest.java
+++ b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/ListWorkflowsRequest.java
@@ -57,78 +57,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private ListWorkflowsRequest(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              parent_ = s;
-              break;
-            }
-          case 16:
-            {
-              pageSize_ = input.readInt32();
-              break;
-            }
-          case 26:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              pageToken_ = s;
-              break;
-            }
-          case 34:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              filter_ = s;
-              break;
-            }
-          case 42:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              orderBy_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1beta.WorkflowsProto
         .internal_static_google_cloud_workflows_v1beta_ListWorkflowsRequest_descriptor;
@@ -408,7 +336,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(orderBy_)) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 5, orderBy_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -432,7 +360,7 @@ public int getSerializedSize() {
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(orderBy_)) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(5, orderBy_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -453,7 +381,7 @@ public boolean equals(final java.lang.Object obj) {
     if (!getPageToken().equals(other.getPageToken())) return false;
     if (!getFilter().equals(other.getFilter())) return false;
     if (!getOrderBy().equals(other.getOrderBy())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -474,7 +402,7 @@ public int hashCode() {
     hash = (53 * hash) + getFilter().hashCode();
     hash = (37 * hash) + ORDER_BY_FIELD_NUMBER;
     hash = (53 * hash) + getOrderBy().hashCode();
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -606,17 +534,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1beta.ListWorkflowsRequest.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -733,7 +654,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1beta.ListWorkflowsRequest
         orderBy_ = other.orderBy_;
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -748,18 +669,61 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1beta.ListWorkflowsRequest parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                parent_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 10
+            case 16:
+              {
+                pageSize_ = input.readInt32();
+
+                break;
+              } // case 16
+            case 26:
+              {
+                pageToken_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 26
+            case 34:
+              {
+                filter_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 34
+            case 42:
+              {
+                orderBy_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 42
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1beta.ListWorkflowsRequest) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -1325,7 +1289,18 @@ public ListWorkflowsRequest parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new ListWorkflowsRequest(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/ListWorkflowsResponse.java b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/ListWorkflowsResponse.java
index 333e4d2906be..16370c3e37cf 100644
--- a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/ListWorkflowsResponse.java
+++ b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/ListWorkflowsResponse.java
@@ -56,80 +56,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private ListWorkflowsResponse(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    int mutable_bitField0_ = 0;
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              if (!((mutable_bitField0_ & 0x00000001) != 0)) {
-                workflows_ = new java.util.ArrayList<com.google.cloud.workflows.v1beta.Workflow>();
-                mutable_bitField0_ |= 0x00000001;
-              }
-              workflows_.add(
-                  input.readMessage(
-                      com.google.cloud.workflows.v1beta.Workflow.parser(), extensionRegistry));
-              break;
-            }
-          case 18:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              nextPageToken_ = s;
-              break;
-            }
-          case 26:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-              if (!((mutable_bitField0_ & 0x00000002) != 0)) {
-                unreachable_ = new com.google.protobuf.LazyStringArrayList();
-                mutable_bitField0_ |= 0x00000002;
-              }
-              unreachable_.add(s);
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      if (((mutable_bitField0_ & 0x00000001) != 0)) {
-        workflows_ = java.util.Collections.unmodifiableList(workflows_);
-      }
-      if (((mutable_bitField0_ & 0x00000002) != 0)) {
-        unreachable_ = unreachable_.getUnmodifiableView();
-      }
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1beta.WorkflowsProto
         .internal_static_google_cloud_workflows_v1beta_ListWorkflowsResponse_descriptor;
@@ -349,7 +275,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     for (int i = 0; i < unreachable_.size(); i++) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 3, unreachable_.getRaw(i));
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -372,7 +298,7 @@ public int getSerializedSize() {
       size += dataSize;
       size += 1 * getUnreachableList().size();
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -391,7 +317,7 @@ public boolean equals(final java.lang.Object obj) {
     if (!getWorkflowsList().equals(other.getWorkflowsList())) return false;
     if (!getNextPageToken().equals(other.getNextPageToken())) return false;
     if (!getUnreachableList().equals(other.getUnreachableList())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -412,7 +338,7 @@ public int hashCode() {
       hash = (37 * hash) + UNREACHABLE_FIELD_NUMBER;
       hash = (53 * hash) + getUnreachableList().hashCode();
     }
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -544,19 +470,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1beta.ListWorkflowsResponse.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {
-        getWorkflowsFieldBuilder();
-      }
     }
 
     @java.lang.Override
@@ -564,10 +481,11 @@ public Builder clear() {
       super.clear();
       if (workflowsBuilder_ == null) {
         workflows_ = java.util.Collections.emptyList();
-        bitField0_ = (bitField0_ & ~0x00000001);
       } else {
+        workflows_ = null;
         workflowsBuilder_.clear();
       }
+      bitField0_ = (bitField0_ & ~0x00000001);
       nextPageToken_ = "";
 
       unreachable_ = com.google.protobuf.LazyStringArrayList.EMPTY;
@@ -706,7 +624,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1beta.ListWorkflowsResponse
         }
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -721,18 +639,57 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1beta.ListWorkflowsResponse parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                com.google.cloud.workflows.v1beta.Workflow m =
+                    input.readMessage(
+                        com.google.cloud.workflows.v1beta.Workflow.parser(), extensionRegistry);
+                if (workflowsBuilder_ == null) {
+                  ensureWorkflowsIsMutable();
+                  workflows_.add(m);
+                } else {
+                  workflowsBuilder_.addMessage(m);
+                }
+                break;
+              } // case 10
+            case 18:
+              {
+                nextPageToken_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 18
+            case 26:
+              {
+                java.lang.String s = input.readStringRequireUtf8();
+                ensureUnreachableIsMutable();
+                unreachable_.add(s);
+                break;
+              } // case 26
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1beta.ListWorkflowsResponse) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -1400,7 +1357,18 @@ public ListWorkflowsResponse parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new ListWorkflowsResponse(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/OperationMetadata.java b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/OperationMetadata.java
index 4966ef9d81e6..6d6f99dff941 100644
--- a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/OperationMetadata.java
+++ b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/OperationMetadata.java
@@ -54,96 +54,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private OperationMetadata(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              com.google.protobuf.Timestamp.Builder subBuilder = null;
-              if (createTime_ != null) {
-                subBuilder = createTime_.toBuilder();
-              }
-              createTime_ =
-                  input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(createTime_);
-                createTime_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 18:
-            {
-              com.google.protobuf.Timestamp.Builder subBuilder = null;
-              if (endTime_ != null) {
-                subBuilder = endTime_.toBuilder();
-              }
-              endTime_ =
-                  input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(endTime_);
-                endTime_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 26:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              target_ = s;
-              break;
-            }
-          case 34:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              verb_ = s;
-              break;
-            }
-          case 42:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              apiVersion_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1beta.WorkflowsProto
         .internal_static_google_cloud_workflows_v1beta_OperationMetadata_descriptor;
@@ -427,7 +337,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(apiVersion_)) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 5, apiVersion_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -451,7 +361,7 @@ public int getSerializedSize() {
     if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(apiVersion_)) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(5, apiVersion_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -478,7 +388,7 @@ public boolean equals(final java.lang.Object obj) {
     if (!getTarget().equals(other.getTarget())) return false;
     if (!getVerb().equals(other.getVerb())) return false;
     if (!getApiVersion().equals(other.getApiVersion())) return false;
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -503,7 +413,7 @@ public int hashCode() {
     hash = (53 * hash) + getVerb().hashCode();
     hash = (37 * hash) + API_VERSION_FIELD_NUMBER;
     hash = (53 * hash) + getApiVersion().hashCode();
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -632,17 +542,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1beta.OperationMetadata.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -774,7 +677,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1beta.OperationMetadata oth
         apiVersion_ = other.apiVersion_;
         onChanged();
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -789,18 +692,61 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1beta.OperationMetadata parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                input.readMessage(getCreateTimeFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 10
+            case 18:
+              {
+                input.readMessage(getEndTimeFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 18
+            case 26:
+              {
+                target_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 26
+            case 34:
+              {
+                verb_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 34
+            case 42:
+              {
+                apiVersion_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 42
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1beta.OperationMetadata) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -1516,7 +1462,18 @@ public OperationMetadata parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new OperationMetadata(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/UpdateWorkflowRequest.java b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/UpdateWorkflowRequest.java
index 24edcf5dbff4..048ea3dea032 100644
--- a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/UpdateWorkflowRequest.java
+++ b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/UpdateWorkflowRequest.java
@@ -52,76 +52,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private UpdateWorkflowRequest(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              com.google.cloud.workflows.v1beta.Workflow.Builder subBuilder = null;
-              if (workflow_ != null) {
-                subBuilder = workflow_.toBuilder();
-              }
-              workflow_ =
-                  input.readMessage(
-                      com.google.cloud.workflows.v1beta.Workflow.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(workflow_);
-                workflow_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 18:
-            {
-              com.google.protobuf.FieldMask.Builder subBuilder = null;
-              if (updateMask_ != null) {
-                subBuilder = updateMask_.toBuilder();
-              }
-              updateMask_ =
-                  input.readMessage(com.google.protobuf.FieldMask.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(updateMask_);
-                updateMask_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1beta.WorkflowsProto
         .internal_static_google_cloud_workflows_v1beta_UpdateWorkflowRequest_descriptor;
@@ -260,7 +190,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (updateMask_ != null) {
       output.writeMessage(2, getUpdateMask());
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -275,7 +205,7 @@ public int getSerializedSize() {
     if (updateMask_ != null) {
       size += com.google.protobuf.CodedOutputStream.computeMessageSize(2, getUpdateMask());
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -299,7 +229,7 @@ public boolean equals(final java.lang.Object obj) {
     if (hasUpdateMask()) {
       if (!getUpdateMask().equals(other.getUpdateMask())) return false;
     }
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -318,7 +248,7 @@ public int hashCode() {
       hash = (37 * hash) + UPDATE_MASK_FIELD_NUMBER;
       hash = (53 * hash) + getUpdateMask().hashCode();
     }
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -450,17 +380,10 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     }
 
     // Construct using com.google.cloud.workflows.v1beta.UpdateWorkflowRequest.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -571,7 +494,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1beta.UpdateWorkflowRequest
       if (other.hasUpdateMask()) {
         mergeUpdateMask(other.getUpdateMask());
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -586,18 +509,43 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1beta.UpdateWorkflowRequest parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                input.readMessage(getWorkflowFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 10
+            case 18:
+              {
+                input.readMessage(getUpdateMaskFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 18
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage =
-            (com.google.cloud.workflows.v1beta.UpdateWorkflowRequest) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -1028,7 +976,18 @@ public UpdateWorkflowRequest parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new UpdateWorkflowRequest(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };
 
diff --git a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/Workflow.java b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/Workflow.java
index 8fce68b86df8..7c6b75b72b2e 100644
--- a/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/Workflow.java
+++ b/java-workflows/proto-google-cloud-workflows-v1beta/src/main/java/com/google/cloud/workflows/v1beta/Workflow.java
@@ -56,146 +56,6 @@ public final com.google.protobuf.UnknownFieldSet getUnknownFields() {
     return this.unknownFields;
   }
 
-  private Workflow(
-      com.google.protobuf.CodedInputStream input,
-      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
-      throws com.google.protobuf.InvalidProtocolBufferException {
-    this();
-    if (extensionRegistry == null) {
-      throw new java.lang.NullPointerException();
-    }
-    int mutable_bitField0_ = 0;
-    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
-        com.google.protobuf.UnknownFieldSet.newBuilder();
-    try {
-      boolean done = false;
-      while (!done) {
-        int tag = input.readTag();
-        switch (tag) {
-          case 0:
-            done = true;
-            break;
-          case 10:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              name_ = s;
-              break;
-            }
-          case 18:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              description_ = s;
-              break;
-            }
-          case 24:
-            {
-              int rawValue = input.readEnum();
-
-              state_ = rawValue;
-              break;
-            }
-          case 34:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              revisionId_ = s;
-              break;
-            }
-          case 42:
-            {
-              com.google.protobuf.Timestamp.Builder subBuilder = null;
-              if (createTime_ != null) {
-                subBuilder = createTime_.toBuilder();
-              }
-              createTime_ =
-                  input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(createTime_);
-                createTime_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 50:
-            {
-              com.google.protobuf.Timestamp.Builder subBuilder = null;
-              if (updateTime_ != null) {
-                subBuilder = updateTime_.toBuilder();
-              }
-              updateTime_ =
-                  input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(updateTime_);
-                updateTime_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 58:
-            {
-              com.google.protobuf.Timestamp.Builder subBuilder = null;
-              if (revisionCreateTime_ != null) {
-                subBuilder = revisionCreateTime_.toBuilder();
-              }
-              revisionCreateTime_ =
-                  input.readMessage(com.google.protobuf.Timestamp.parser(), extensionRegistry);
-              if (subBuilder != null) {
-                subBuilder.mergeFrom(revisionCreateTime_);
-                revisionCreateTime_ = subBuilder.buildPartial();
-              }
-
-              break;
-            }
-          case 66:
-            {
-              if (!((mutable_bitField0_ & 0x00000001) != 0)) {
-                labels_ =
-                    com.google.protobuf.MapField.newMapField(LabelsDefaultEntryHolder.defaultEntry);
-                mutable_bitField0_ |= 0x00000001;
-              }
-              com.google.protobuf.MapEntry<java.lang.String, java.lang.String> labels__ =
-                  input.readMessage(
-                      LabelsDefaultEntryHolder.defaultEntry.getParserForType(), extensionRegistry);
-              labels_.getMutableMap().put(labels__.getKey(), labels__.getValue());
-              break;
-            }
-          case 74:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-
-              serviceAccount_ = s;
-              break;
-            }
-          case 82:
-            {
-              java.lang.String s = input.readStringRequireUtf8();
-              sourceCodeCase_ = 10;
-              sourceCode_ = s;
-              break;
-            }
-          default:
-            {
-              if (!parseUnknownField(input, unknownFields, extensionRegistry, tag)) {
-                done = true;
-              }
-              break;
-            }
-        }
-      }
-    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-      throw e.setUnfinishedMessage(this);
-    } catch (com.google.protobuf.UninitializedMessageException e) {
-      throw e.asInvalidProtocolBufferException().setUnfinishedMessage(this);
-    } catch (java.io.IOException e) {
-      throw new com.google.protobuf.InvalidProtocolBufferException(e).setUnfinishedMessage(this);
-    } finally {
-      this.unknownFields = unknownFields.build();
-      makeExtensionsImmutable();
-    }
-  }
-
   public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
     return com.google.cloud.workflows.v1beta.WorkflowsProto
         .internal_static_google_cloud_workflows_v1beta_Workflow_descriptor;
@@ -1056,7 +916,7 @@ public void writeTo(com.google.protobuf.CodedOutputStream output) throws java.io
     if (sourceCodeCase_ == 10) {
       com.google.protobuf.GeneratedMessageV3.writeString(output, 10, sourceCode_);
     }
-    unknownFields.writeTo(output);
+    getUnknownFields().writeTo(output);
   }
 
   @java.lang.Override
@@ -1102,7 +962,7 @@ public int getSerializedSize() {
     if (sourceCodeCase_ == 10) {
       size += com.google.protobuf.GeneratedMessageV3.computeStringSize(10, sourceCode_);
     }
-    size += unknownFields.getSerializedSize();
+    size += getUnknownFields().getSerializedSize();
     memoizedSize = size;
     return size;
   }
@@ -1144,7 +1004,7 @@ public boolean equals(final java.lang.Object obj) {
       case 0:
       default:
     }
-    if (!unknownFields.equals(other.unknownFields)) return false;
+    if (!getUnknownFields().equals(other.getUnknownFields())) return false;
     return true;
   }
 
@@ -1189,7 +1049,7 @@ public int hashCode() {
       case 0:
       default:
     }
-    hash = (29 * hash) + unknownFields.hashCode();
+    hash = (29 * hash) + getUnknownFields().hashCode();
     memoizedHashCode = hash;
     return hash;
   }
@@ -1338,17 +1198,10 @@ protected com.google.protobuf.MapField internalGetMutableMapField(int number) {
     }
 
     // Construct using com.google.cloud.workflows.v1beta.Workflow.newBuilder()
-    private Builder() {
-      maybeForceBuilderInitialization();
-    }
+    private Builder() {}
 
     private Builder(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
       super(parent);
-      maybeForceBuilderInitialization();
-    }
-
-    private void maybeForceBuilderInitialization() {
-      if (com.google.protobuf.GeneratedMessageV3.alwaysUseFieldBuilders) {}
     }
 
     @java.lang.Override
@@ -1530,7 +1383,7 @@ public Builder mergeFrom(com.google.cloud.workflows.v1beta.Workflow other) {
             break;
           }
       }
-      this.mergeUnknownFields(other.unknownFields);
+      this.mergeUnknownFields(other.getUnknownFields());
       onChanged();
       return this;
     }
@@ -1545,17 +1398,98 @@ public Builder mergeFrom(
         com.google.protobuf.CodedInputStream input,
         com.google.protobuf.ExtensionRegistryLite extensionRegistry)
         throws java.io.IOException {
-      com.google.cloud.workflows.v1beta.Workflow parsedMessage = null;
+      if (extensionRegistry == null) {
+        throw new java.lang.NullPointerException();
+      }
       try {
-        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            case 10:
+              {
+                name_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 10
+            case 18:
+              {
+                description_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 18
+            case 24:
+              {
+                state_ = input.readEnum();
+
+                break;
+              } // case 24
+            case 34:
+              {
+                revisionId_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 34
+            case 42:
+              {
+                input.readMessage(getCreateTimeFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 42
+            case 50:
+              {
+                input.readMessage(getUpdateTimeFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 50
+            case 58:
+              {
+                input.readMessage(
+                    getRevisionCreateTimeFieldBuilder().getBuilder(), extensionRegistry);
+
+                break;
+              } // case 58
+            case 66:
+              {
+                com.google.protobuf.MapEntry<java.lang.String, java.lang.String> labels__ =
+                    input.readMessage(
+                        LabelsDefaultEntryHolder.defaultEntry.getParserForType(),
+                        extensionRegistry);
+                internalGetMutableLabels()
+                    .getMutableMap()
+                    .put(labels__.getKey(), labels__.getValue());
+                break;
+              } // case 66
+            case 74:
+              {
+                serviceAccount_ = input.readStringRequireUtf8();
+
+                break;
+              } // case 74
+            case 82:
+              {
+                java.lang.String s = input.readStringRequireUtf8();
+                sourceCodeCase_ = 10;
+                sourceCode_ = s;
+                break;
+              } // case 82
+            default:
+              {
+                if (!super.parseUnknownField(input, extensionRegistry, tag)) {
+                  done = true; // was an endgroup tag
+                }
+                break;
+              } // default:
+          } // switch (tag)
+        } // while (!done)
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
-        parsedMessage = (com.google.cloud.workflows.v1beta.Workflow) e.getUnfinishedMessage();
         throw e.unwrapIOException();
       } finally {
-        if (parsedMessage != null) {
-          mergeFrom(parsedMessage);
-        }
-      }
+        onChanged();
+      } // finally
       return this;
     }
 
@@ -3158,7 +3092,18 @@ public Workflow parsePartialFrom(
             com.google.protobuf.CodedInputStream input,
             com.google.protobuf.ExtensionRegistryLite extensionRegistry)
             throws com.google.protobuf.InvalidProtocolBufferException {
-          return new Workflow(input, extensionRegistry);
+          Builder builder = newBuilder();
+          try {
+            builder.mergeFrom(input, extensionRegistry);
+          } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+            throw e.setUnfinishedMessage(builder.buildPartial());
+          } catch (com.google.protobuf.UninitializedMessageException e) {
+            throw e.asInvalidProtocolBufferException().setUnfinishedMessage(builder.buildPartial());
+          } catch (java.io.IOException e) {
+            throw new com.google.protobuf.InvalidProtocolBufferException(e)
+                .setUnfinishedMessage(builder.buildPartial());
+          }
+          return builder.buildPartial();
         }
       };