diff --git a/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/IamCredentialsClient.java b/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/IamCredentialsClient.java
index cb80a9634e0f..1282bb753b0d 100644
--- a/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/IamCredentialsClient.java
+++ b/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/IamCredentialsClient.java
@@ -42,8 +42,11 @@
  * calls that map to API methods. Sample code to get started:
  *
  * <pre>{@code
- * // This snippet has been automatically generated for illustrative purposes only.
- * // It may require modifications to work in your environment.
+ * // This snippet has been automatically generated and should be regarded as a code template only.
+ * // It will require modifications to work:
+ * // - It may require correct/in-range values for request initialization.
+ * // - It may require specifying regional endpoints when creating the service client as shown in
+ * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
  * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
  *   ServiceAccountName name = ServiceAccountName.of("[PROJECT]", "[SERVICE_ACCOUNT]");
  *   List<String> delegates = new ArrayList<>();
@@ -83,8 +86,11 @@
  * <p>To customize credentials:
  *
  * <pre>{@code
- * // This snippet has been automatically generated for illustrative purposes only.
- * // It may require modifications to work in your environment.
+ * // This snippet has been automatically generated and should be regarded as a code template only.
+ * // It will require modifications to work:
+ * // - It may require correct/in-range values for request initialization.
+ * // - It may require specifying regional endpoints when creating the service client as shown in
+ * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
  * IamCredentialsSettings iamCredentialsSettings =
  *     IamCredentialsSettings.newBuilder()
  *         .setCredentialsProvider(FixedCredentialsProvider.create(myCredentials))
@@ -95,8 +101,11 @@
  * <p>To customize the endpoint:
  *
  * <pre>{@code
- * // This snippet has been automatically generated for illustrative purposes only.
- * // It may require modifications to work in your environment.
+ * // This snippet has been automatically generated and should be regarded as a code template only.
+ * // It will require modifications to work:
+ * // - It may require correct/in-range values for request initialization.
+ * // - It may require specifying regional endpoints when creating the service client as shown in
+ * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
  * IamCredentialsSettings iamCredentialsSettings =
  *     IamCredentialsSettings.newBuilder().setEndpoint(myEndpoint).build();
  * IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create(iamCredentialsSettings);
@@ -106,8 +115,11 @@
  * the wire:
  *
  * <pre>{@code
- * // This snippet has been automatically generated for illustrative purposes only.
- * // It may require modifications to work in your environment.
+ * // This snippet has been automatically generated and should be regarded as a code template only.
+ * // It will require modifications to work:
+ * // - It may require correct/in-range values for request initialization.
+ * // - It may require specifying regional endpoints when creating the service client as shown in
+ * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
  * IamCredentialsSettings iamCredentialsSettings =
  *     IamCredentialsSettings.newBuilder()
  *         .setTransportChannelProvider(
@@ -175,8 +187,11 @@ public IamCredentialsStub getStub() {
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   ServiceAccountName name = ServiceAccountName.of("[PROJECT]", "[SERVICE_ACCOUNT]");
    *   List<String> delegates = new ArrayList<>();
@@ -226,8 +241,11 @@ public final GenerateAccessTokenResponse generateAccessToken(
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   String name = ServiceAccountName.of("[PROJECT]", "[SERVICE_ACCOUNT]").toString();
    *   List<String> delegates = new ArrayList<>();
@@ -277,8 +295,11 @@ public final GenerateAccessTokenResponse generateAccessToken(
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   GenerateAccessTokenRequest request =
    *       GenerateAccessTokenRequest.newBuilder()
@@ -305,8 +326,11 @@ public final GenerateAccessTokenResponse generateAccessToken(GenerateAccessToken
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   GenerateAccessTokenRequest request =
    *       GenerateAccessTokenRequest.newBuilder()
@@ -334,8 +358,11 @@ public final GenerateAccessTokenResponse generateAccessToken(GenerateAccessToken
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   ServiceAccountName name = ServiceAccountName.of("[PROJECT]", "[SERVICE_ACCOUNT]");
    *   List<String> delegates = new ArrayList<>();
@@ -383,8 +410,11 @@ public final GenerateIdTokenResponse generateIdToken(
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   String name = ServiceAccountName.of("[PROJECT]", "[SERVICE_ACCOUNT]").toString();
    *   List<String> delegates = new ArrayList<>();
@@ -432,8 +462,11 @@ public final GenerateIdTokenResponse generateIdToken(
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   GenerateIdTokenRequest request =
    *       GenerateIdTokenRequest.newBuilder()
@@ -460,8 +493,11 @@ public final GenerateIdTokenResponse generateIdToken(GenerateIdTokenRequest requ
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   GenerateIdTokenRequest request =
    *       GenerateIdTokenRequest.newBuilder()
@@ -489,8 +525,11 @@ public final GenerateIdTokenResponse generateIdToken(GenerateIdTokenRequest requ
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   ServiceAccountName name = ServiceAccountName.of("[PROJECT]", "[SERVICE_ACCOUNT]");
    *   List<String> delegates = new ArrayList<>();
@@ -532,8 +571,11 @@ public final SignBlobResponse signBlob(
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   String name = ServiceAccountName.of("[PROJECT]", "[SERVICE_ACCOUNT]").toString();
    *   List<String> delegates = new ArrayList<>();
@@ -574,8 +616,11 @@ public final SignBlobResponse signBlob(String name, List<String> delegates, Byte
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   SignBlobRequest request =
    *       SignBlobRequest.newBuilder()
@@ -601,8 +646,11 @@ public final SignBlobResponse signBlob(SignBlobRequest request) {
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   SignBlobRequest request =
    *       SignBlobRequest.newBuilder()
@@ -628,8 +676,11 @@ public final UnaryCallable<SignBlobRequest, SignBlobResponse> signBlobCallable()
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   ServiceAccountName name = ServiceAccountName.of("[PROJECT]", "[SERVICE_ACCOUNT]");
    *   List<String> delegates = new ArrayList<>();
@@ -671,8 +722,11 @@ public final SignJwtResponse signJwt(
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   String name = ServiceAccountName.of("[PROJECT]", "[SERVICE_ACCOUNT]").toString();
    *   List<String> delegates = new ArrayList<>();
@@ -713,8 +767,11 @@ public final SignJwtResponse signJwt(String name, List<String> delegates, String
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   SignJwtRequest request =
    *       SignJwtRequest.newBuilder()
@@ -740,8 +797,11 @@ public final SignJwtResponse signJwt(SignJwtRequest request) {
    * <p>Sample code:
    *
    * <pre>{@code
-   * // This snippet has been automatically generated for illustrative purposes only.
-   * // It may require modifications to work in your environment.
+   * // This snippet has been automatically generated and should be regarded as a code template only.
+   * // It will require modifications to work:
+   * // - It may require correct/in-range values for request initialization.
+   * // - It may require specifying regional endpoints when creating the service client as shown in
+   * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
    * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
    *   SignJwtRequest request =
    *       SignJwtRequest.newBuilder()
diff --git a/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/IamCredentialsSettings.java b/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/IamCredentialsSettings.java
index e685220422e9..e8bf7bebb7ee 100644
--- a/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/IamCredentialsSettings.java
+++ b/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/IamCredentialsSettings.java
@@ -51,8 +51,11 @@
  * <p>For example, to set the total timeout of generateAccessToken to 30 seconds:
  *
  * <pre>{@code
- * // This snippet has been automatically generated for illustrative purposes only.
- * // It may require modifications to work in your environment.
+ * // This snippet has been automatically generated and should be regarded as a code template only.
+ * // It will require modifications to work:
+ * // - It may require correct/in-range values for request initialization.
+ * // - It may require specifying regional endpoints when creating the service client as shown in
+ * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
  * IamCredentialsSettings.Builder iamCredentialsSettingsBuilder =
  *     IamCredentialsSettings.newBuilder();
  * iamCredentialsSettingsBuilder
diff --git a/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/package-info.java b/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/package-info.java
index da4fef9f2502..ab0c43dcfc65 100644
--- a/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/package-info.java
+++ b/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/package-info.java
@@ -31,8 +31,11 @@
  * <p>Sample for IamCredentialsClient:
  *
  * <pre>{@code
- * // This snippet has been automatically generated for illustrative purposes only.
- * // It may require modifications to work in your environment.
+ * // This snippet has been automatically generated and should be regarded as a code template only.
+ * // It will require modifications to work:
+ * // - It may require correct/in-range values for request initialization.
+ * // - It may require specifying regional endpoints when creating the service client as shown in
+ * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
  * try (IamCredentialsClient iamCredentialsClient = IamCredentialsClient.create()) {
  *   ServiceAccountName name = ServiceAccountName.of("[PROJECT]", "[SERVICE_ACCOUNT]");
  *   List<String> delegates = new ArrayList<>();
diff --git a/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/stub/HttpJsonIamCredentialsStub.java b/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/stub/HttpJsonIamCredentialsStub.java
index 0c0aef8904fd..e0d482144239 100644
--- a/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/stub/HttpJsonIamCredentialsStub.java
+++ b/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/stub/HttpJsonIamCredentialsStub.java
@@ -83,7 +83,7 @@ public class HttpJsonIamCredentialsStub extends IamCredentialsStub {
                       .setRequestBodyExtractor(
                           request ->
                               ProtoRestSerializer.create()
-                                  .toBody("*", request.toBuilder().clearName().build()))
+                                  .toBody("*", request.toBuilder().clearName().build(), false))
                       .build())
               .setResponseParser(
                   ProtoMessageResponseParser.<GenerateAccessTokenResponse>newBuilder()
@@ -119,7 +119,7 @@ public class HttpJsonIamCredentialsStub extends IamCredentialsStub {
                       .setRequestBodyExtractor(
                           request ->
                               ProtoRestSerializer.create()
-                                  .toBody("*", request.toBuilder().clearName().build()))
+                                  .toBody("*", request.toBuilder().clearName().build(), false))
                       .build())
               .setResponseParser(
                   ProtoMessageResponseParser.<GenerateIdTokenResponse>newBuilder()
@@ -155,7 +155,7 @@ public class HttpJsonIamCredentialsStub extends IamCredentialsStub {
                       .setRequestBodyExtractor(
                           request ->
                               ProtoRestSerializer.create()
-                                  .toBody("*", request.toBuilder().clearName().build()))
+                                  .toBody("*", request.toBuilder().clearName().build(), false))
                       .build())
               .setResponseParser(
                   ProtoMessageResponseParser.<SignBlobResponse>newBuilder()
@@ -191,7 +191,7 @@ public class HttpJsonIamCredentialsStub extends IamCredentialsStub {
                       .setRequestBodyExtractor(
                           request ->
                               ProtoRestSerializer.create()
-                                  .toBody("*", request.toBuilder().clearName().build()))
+                                  .toBody("*", request.toBuilder().clearName().build(), false))
                       .build())
               .setResponseParser(
                   ProtoMessageResponseParser.<SignJwtResponse>newBuilder()
diff --git a/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/stub/IamCredentialsStubSettings.java b/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/stub/IamCredentialsStubSettings.java
index 572e56efde1a..e5277821f606 100644
--- a/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/stub/IamCredentialsStubSettings.java
+++ b/java-iamcredentials/google-cloud-iamcredentials/src/main/java/com/google/cloud/iam/credentials/v1/stub/IamCredentialsStubSettings.java
@@ -70,8 +70,11 @@
  * <p>For example, to set the total timeout of generateAccessToken to 30 seconds:
  *
  * <pre>{@code
- * // This snippet has been automatically generated for illustrative purposes only.
- * // It may require modifications to work in your environment.
+ * // This snippet has been automatically generated and should be regarded as a code template only.
+ * // It will require modifications to work:
+ * // - It may require correct/in-range values for request initialization.
+ * // - It may require specifying regional endpoints when creating the service client as shown in
+ * // https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
  * IamCredentialsStubSettings.Builder iamCredentialsSettingsBuilder =
  *     IamCredentialsStubSettings.newBuilder();
  * iamCredentialsSettingsBuilder