diff --git a/samples/generated/v1/snippet_metadata.google.storagetransfer.v1.json b/samples/generated/v1/snippet_metadata.google.storagetransfer.v1.json
index df5eecb..31e8938 100644
--- a/samples/generated/v1/snippet_metadata.google.storagetransfer.v1.json
+++ b/samples/generated/v1/snippet_metadata.google.storagetransfer.v1.json
@@ -22,7 +22,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 51,
+                    "end": 54,
                     "type": "FULL"
                 }
             ],
@@ -62,7 +62,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 50,
+                    "end": 53,
                     "type": "FULL"
                 }
             ],
@@ -102,7 +102,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 83,
+                    "end": 86,
                     "type": "FULL"
                 }
             ],
@@ -154,7 +154,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 56,
+                    "end": 59,
                     "type": "FULL"
                 }
             ],
@@ -198,7 +198,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 70,
+                    "end": 73,
                     "type": "FULL"
                 }
             ],
@@ -246,7 +246,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 50,
+                    "end": 53,
                     "type": "FULL"
                 }
             ],
@@ -286,7 +286,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 50,
+                    "end": 53,
                     "type": "FULL"
                 }
             ],
@@ -326,7 +326,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 57,
+                    "end": 60,
                     "type": "FULL"
                 }
             ],
@@ -370,7 +370,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 70,
+                    "end": 73,
                     "type": "FULL"
                 }
             ],
@@ -418,7 +418,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 65,
+                    "end": 68,
                     "type": "FULL"
                 }
             ],
@@ -462,7 +462,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 50,
+                    "end": 53,
                     "type": "FULL"
                 }
             ],
@@ -502,7 +502,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 69,
+                    "end": 72,
                     "type": "FULL"
                 }
             ],
@@ -554,7 +554,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 50,
+                    "end": 53,
                     "type": "FULL"
                 }
             ],
diff --git a/samples/generated/v1/storage_transfer_service.create_agent_pool.js b/samples/generated/v1/storage_transfer_service.create_agent_pool.js
index b8ab5e8..ed5464a 100644
--- a/samples/generated/v1/storage_transfer_service.create_agent_pool.js
+++ b/samples/generated/v1/storage_transfer_service.create_agent_pool.js
@@ -23,6 +23,9 @@
 function main(projectId, agentPool, agentPoolId) {
   // [START storagetransfer_v1_generated_StorageTransferService_CreateAgentPool_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.create_transfer_job.js b/samples/generated/v1/storage_transfer_service.create_transfer_job.js
index 60f7402..5daf776 100644
--- a/samples/generated/v1/storage_transfer_service.create_transfer_job.js
+++ b/samples/generated/v1/storage_transfer_service.create_transfer_job.js
@@ -23,6 +23,9 @@
 function main(transferJob) {
   // [START storagetransfer_v1_generated_StorageTransferService_CreateTransferJob_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.delete_agent_pool.js b/samples/generated/v1/storage_transfer_service.delete_agent_pool.js
index 2435903..fe2d324 100644
--- a/samples/generated/v1/storage_transfer_service.delete_agent_pool.js
+++ b/samples/generated/v1/storage_transfer_service.delete_agent_pool.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START storagetransfer_v1_generated_StorageTransferService_DeleteAgentPool_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.get_agent_pool.js b/samples/generated/v1/storage_transfer_service.get_agent_pool.js
index fa2a1ef..4b30734 100644
--- a/samples/generated/v1/storage_transfer_service.get_agent_pool.js
+++ b/samples/generated/v1/storage_transfer_service.get_agent_pool.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START storagetransfer_v1_generated_StorageTransferService_GetAgentPool_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.get_google_service_account.js b/samples/generated/v1/storage_transfer_service.get_google_service_account.js
index 7c588b9..1b8411e 100644
--- a/samples/generated/v1/storage_transfer_service.get_google_service_account.js
+++ b/samples/generated/v1/storage_transfer_service.get_google_service_account.js
@@ -23,6 +23,9 @@
 function main(projectId) {
   // [START storagetransfer_v1_generated_StorageTransferService_GetGoogleServiceAccount_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.get_transfer_job.js b/samples/generated/v1/storage_transfer_service.get_transfer_job.js
index 46ff036..c7cbd13 100644
--- a/samples/generated/v1/storage_transfer_service.get_transfer_job.js
+++ b/samples/generated/v1/storage_transfer_service.get_transfer_job.js
@@ -23,6 +23,9 @@
 function main(jobName, projectId) {
   // [START storagetransfer_v1_generated_StorageTransferService_GetTransferJob_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.list_agent_pools.js b/samples/generated/v1/storage_transfer_service.list_agent_pools.js
index 2fadae1..636a133 100644
--- a/samples/generated/v1/storage_transfer_service.list_agent_pools.js
+++ b/samples/generated/v1/storage_transfer_service.list_agent_pools.js
@@ -23,6 +23,9 @@
 function main(projectId) {
   // [START storagetransfer_v1_generated_StorageTransferService_ListAgentPools_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.list_transfer_jobs.js b/samples/generated/v1/storage_transfer_service.list_transfer_jobs.js
index 09b0a5a..fa1d170 100644
--- a/samples/generated/v1/storage_transfer_service.list_transfer_jobs.js
+++ b/samples/generated/v1/storage_transfer_service.list_transfer_jobs.js
@@ -23,6 +23,9 @@
 function main(filter) {
   // [START storagetransfer_v1_generated_StorageTransferService_ListTransferJobs_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.pause_transfer_operation.js b/samples/generated/v1/storage_transfer_service.pause_transfer_operation.js
index 8c92715..9a11fd3 100644
--- a/samples/generated/v1/storage_transfer_service.pause_transfer_operation.js
+++ b/samples/generated/v1/storage_transfer_service.pause_transfer_operation.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START storagetransfer_v1_generated_StorageTransferService_PauseTransferOperation_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.resume_transfer_operation.js b/samples/generated/v1/storage_transfer_service.resume_transfer_operation.js
index 826857f..565ac82 100644
--- a/samples/generated/v1/storage_transfer_service.resume_transfer_operation.js
+++ b/samples/generated/v1/storage_transfer_service.resume_transfer_operation.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START storagetransfer_v1_generated_StorageTransferService_ResumeTransferOperation_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.run_transfer_job.js b/samples/generated/v1/storage_transfer_service.run_transfer_job.js
index ef1e7da..ce83387 100644
--- a/samples/generated/v1/storage_transfer_service.run_transfer_job.js
+++ b/samples/generated/v1/storage_transfer_service.run_transfer_job.js
@@ -23,6 +23,9 @@
 function main(jobName, projectId) {
   // [START storagetransfer_v1_generated_StorageTransferService_RunTransferJob_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.update_agent_pool.js b/samples/generated/v1/storage_transfer_service.update_agent_pool.js
index 5b9d842..b2cf855 100644
--- a/samples/generated/v1/storage_transfer_service.update_agent_pool.js
+++ b/samples/generated/v1/storage_transfer_service.update_agent_pool.js
@@ -23,6 +23,9 @@
 function main(agentPool) {
   // [START storagetransfer_v1_generated_StorageTransferService_UpdateAgentPool_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/samples/generated/v1/storage_transfer_service.update_transfer_job.js b/samples/generated/v1/storage_transfer_service.update_transfer_job.js
index 161e303..2ae0d93 100644
--- a/samples/generated/v1/storage_transfer_service.update_transfer_job.js
+++ b/samples/generated/v1/storage_transfer_service.update_transfer_job.js
@@ -23,6 +23,9 @@
 function main(jobName, projectId, transferJob) {
   // [START storagetransfer_v1_generated_StorageTransferService_UpdateTransferJob_async]
   /**
+   * 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.
    * TODO(developer): Uncomment these variables before running the sample.
    */
   /**
diff --git a/src/v1/storage_transfer_service_client.ts b/src/v1/storage_transfer_service_client.ts
index 3248286..c32b4f8 100644
--- a/src/v1/storage_transfer_service_client.ts
+++ b/src/v1/storage_transfer_service_client.ts
@@ -30,7 +30,6 @@ import {
 } from 'google-gax';
 
 import {Transform} from 'stream';
-import {RequestType} from 'google-gax/build/src/apitypes';
 import * as protos from '../../protos/protos';
 import jsonProtos = require('../../protos/protos.json');
 /**
@@ -321,7 +320,8 @@ export class StorageTransferServiceClient {
       const apiCall = this._gaxModule.createApiCall(
         callPromise,
         this._defaults[methodName],
-        descriptor
+        descriptor,
+        this._opts.fallback
       );
 
       this.innerApiCalls[methodName] = apiCall;
@@ -1527,7 +1527,7 @@ export class StorageTransferServiceClient {
     const decodeOperation = new gax.Operation(
       operation,
       this.descriptors.longrunning.runTransferJob,
-      gax.createDefaultBackoffSettings()
+      this._gaxModule.createDefaultBackoffSettings()
     );
     return decodeOperation as LROperation<
       protos.google.protobuf.Empty,
@@ -1685,7 +1685,7 @@ export class StorageTransferServiceClient {
     const callSettings = defaultCallSettings.merge(options);
     this.initialize();
     return this.descriptors.page.listTransferJobs.createStream(
-      this.innerApiCalls.listTransferJobs as gax.GaxCall,
+      this.innerApiCalls.listTransferJobs as GaxCall,
       request,
       callSettings
     );
@@ -1740,7 +1740,7 @@ export class StorageTransferServiceClient {
     this.initialize();
     return this.descriptors.page.listTransferJobs.asyncIterate(
       this.innerApiCalls['listTransferJobs'] as GaxCall,
-      request as unknown as RequestType,
+      request as {},
       callSettings
     ) as AsyncIterable<protos.google.storagetransfer.v1.ITransferJob>;
   }
@@ -1899,7 +1899,7 @@ export class StorageTransferServiceClient {
     const callSettings = defaultCallSettings.merge(options);
     this.initialize();
     return this.descriptors.page.listAgentPools.createStream(
-      this.innerApiCalls.listAgentPools as gax.GaxCall,
+      this.innerApiCalls.listAgentPools as GaxCall,
       request,
       callSettings
     );
@@ -1956,7 +1956,7 @@ export class StorageTransferServiceClient {
     this.initialize();
     return this.descriptors.page.listAgentPools.asyncIterate(
       this.innerApiCalls['listAgentPools'] as GaxCall,
-      request as unknown as RequestType,
+      request as {},
       callSettings
     ) as AsyncIterable<protos.google.storagetransfer.v1.IAgentPool>;
   }
diff --git a/test/gapic_storage_transfer_service_v1.ts b/test/gapic_storage_transfer_service_v1.ts
index 99d5cd7..433e373 100644
--- a/test/gapic_storage_transfer_service_v1.ts
+++ b/test/gapic_storage_transfer_service_v1.ts
@@ -145,109 +145,113 @@ function stubAsyncIterationCall<ResponseType>(
 }
 
 describe('v1.StorageTransferServiceClient', () => {
-  it('has servicePath', () => {
-    const servicePath =
-      storagetransferserviceModule.v1.StorageTransferServiceClient.servicePath;
-    assert(servicePath);
-  });
+  describe('Common methods', () => {
+    it('has servicePath', () => {
+      const servicePath =
+        storagetransferserviceModule.v1.StorageTransferServiceClient
+          .servicePath;
+      assert(servicePath);
+    });
 
-  it('has apiEndpoint', () => {
-    const apiEndpoint =
-      storagetransferserviceModule.v1.StorageTransferServiceClient.apiEndpoint;
-    assert(apiEndpoint);
-  });
+    it('has apiEndpoint', () => {
+      const apiEndpoint =
+        storagetransferserviceModule.v1.StorageTransferServiceClient
+          .apiEndpoint;
+      assert(apiEndpoint);
+    });
 
-  it('has port', () => {
-    const port =
-      storagetransferserviceModule.v1.StorageTransferServiceClient.port;
-    assert(port);
-    assert(typeof port === 'number');
-  });
+    it('has port', () => {
+      const port =
+        storagetransferserviceModule.v1.StorageTransferServiceClient.port;
+      assert(port);
+      assert(typeof port === 'number');
+    });
 
-  it('should create a client with no option', () => {
-    const client =
-      new storagetransferserviceModule.v1.StorageTransferServiceClient();
-    assert(client);
-  });
+    it('should create a client with no option', () => {
+      const client =
+        new storagetransferserviceModule.v1.StorageTransferServiceClient();
+      assert(client);
+    });
 
-  it('should create a client with gRPC fallback', () => {
-    const client =
-      new storagetransferserviceModule.v1.StorageTransferServiceClient({
-        fallback: true,
-      });
-    assert(client);
-  });
+    it('should create a client with gRPC fallback', () => {
+      const client =
+        new storagetransferserviceModule.v1.StorageTransferServiceClient({
+          fallback: true,
+        });
+      assert(client);
+    });
 
-  it('has initialize method and supports deferred initialization', async () => {
-    const client =
-      new storagetransferserviceModule.v1.StorageTransferServiceClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
-      });
-    assert.strictEqual(client.storageTransferServiceStub, undefined);
-    await client.initialize();
-    assert(client.storageTransferServiceStub);
-  });
+    it('has initialize method and supports deferred initialization', async () => {
+      const client =
+        new storagetransferserviceModule.v1.StorageTransferServiceClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      assert.strictEqual(client.storageTransferServiceStub, undefined);
+      await client.initialize();
+      assert(client.storageTransferServiceStub);
+    });
 
-  it('has close method for the initialized client', done => {
-    const client =
-      new storagetransferserviceModule.v1.StorageTransferServiceClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
+    it('has close method for the initialized client', done => {
+      const client =
+        new storagetransferserviceModule.v1.StorageTransferServiceClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      client.initialize();
+      assert(client.storageTransferServiceStub);
+      client.close().then(() => {
+        done();
       });
-    client.initialize();
-    assert(client.storageTransferServiceStub);
-    client.close().then(() => {
-      done();
     });
-  });
 
-  it('has close method for the non-initialized client', done => {
-    const client =
-      new storagetransferserviceModule.v1.StorageTransferServiceClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
+    it('has close method for the non-initialized client', done => {
+      const client =
+        new storagetransferserviceModule.v1.StorageTransferServiceClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      assert.strictEqual(client.storageTransferServiceStub, undefined);
+      client.close().then(() => {
+        done();
       });
-    assert.strictEqual(client.storageTransferServiceStub, undefined);
-    client.close().then(() => {
-      done();
     });
-  });
 
-  it('has getProjectId method', async () => {
-    const fakeProjectId = 'fake-project-id';
-    const client =
-      new storagetransferserviceModule.v1.StorageTransferServiceClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
-      });
-    client.auth.getProjectId = sinon.stub().resolves(fakeProjectId);
-    const result = await client.getProjectId();
-    assert.strictEqual(result, fakeProjectId);
-    assert((client.auth.getProjectId as SinonStub).calledWithExactly());
-  });
+    it('has getProjectId method', async () => {
+      const fakeProjectId = 'fake-project-id';
+      const client =
+        new storagetransferserviceModule.v1.StorageTransferServiceClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      client.auth.getProjectId = sinon.stub().resolves(fakeProjectId);
+      const result = await client.getProjectId();
+      assert.strictEqual(result, fakeProjectId);
+      assert((client.auth.getProjectId as SinonStub).calledWithExactly());
+    });
 
-  it('has getProjectId method with callback', async () => {
-    const fakeProjectId = 'fake-project-id';
-    const client =
-      new storagetransferserviceModule.v1.StorageTransferServiceClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
-      });
-    client.auth.getProjectId = sinon
-      .stub()
-      .callsArgWith(0, null, fakeProjectId);
-    const promise = new Promise((resolve, reject) => {
-      client.getProjectId((err?: Error | null, projectId?: string | null) => {
-        if (err) {
-          reject(err);
-        } else {
-          resolve(projectId);
-        }
+    it('has getProjectId method with callback', async () => {
+      const fakeProjectId = 'fake-project-id';
+      const client =
+        new storagetransferserviceModule.v1.StorageTransferServiceClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      client.auth.getProjectId = sinon
+        .stub()
+        .callsArgWith(0, null, fakeProjectId);
+      const promise = new Promise((resolve, reject) => {
+        client.getProjectId((err?: Error | null, projectId?: string | null) => {
+          if (err) {
+            reject(err);
+          } else {
+            resolve(projectId);
+          }
+        });
       });
+      const result = await promise;
+      assert.strictEqual(result, fakeProjectId);
     });
-    const result = await promise;
-    assert.strictEqual(result, fakeProjectId);
   });
 
   describe('getGoogleServiceAccount', () => {