diff --git a/samples/generated/v1/essential_contacts_service.compute_contacts.js b/samples/generated/v1/essential_contacts_service.compute_contacts.js
index 00d490a..40dacdb 100644
--- a/samples/generated/v1/essential_contacts_service.compute_contacts.js
+++ b/samples/generated/v1/essential_contacts_service.compute_contacts.js
@@ -23,6 +23,9 @@
 function main(parent) {
   // [START essentialcontacts_v1_generated_EssentialContactsService_ComputeContacts_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/essential_contacts_service.create_contact.js b/samples/generated/v1/essential_contacts_service.create_contact.js
index f1fd31c..a087e10 100644
--- a/samples/generated/v1/essential_contacts_service.create_contact.js
+++ b/samples/generated/v1/essential_contacts_service.create_contact.js
@@ -23,6 +23,9 @@
 function main(parent, contact) {
   // [START essentialcontacts_v1_generated_EssentialContactsService_CreateContact_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/essential_contacts_service.delete_contact.js b/samples/generated/v1/essential_contacts_service.delete_contact.js
index 3d046c6..6f5d017 100644
--- a/samples/generated/v1/essential_contacts_service.delete_contact.js
+++ b/samples/generated/v1/essential_contacts_service.delete_contact.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START essentialcontacts_v1_generated_EssentialContactsService_DeleteContact_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/essential_contacts_service.get_contact.js b/samples/generated/v1/essential_contacts_service.get_contact.js
index 7251622..c62013a 100644
--- a/samples/generated/v1/essential_contacts_service.get_contact.js
+++ b/samples/generated/v1/essential_contacts_service.get_contact.js
@@ -23,6 +23,9 @@
 function main(name) {
   // [START essentialcontacts_v1_generated_EssentialContactsService_GetContact_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/essential_contacts_service.list_contacts.js b/samples/generated/v1/essential_contacts_service.list_contacts.js
index 2c6469d..ed35bd7 100644
--- a/samples/generated/v1/essential_contacts_service.list_contacts.js
+++ b/samples/generated/v1/essential_contacts_service.list_contacts.js
@@ -23,6 +23,9 @@
 function main(parent) {
   // [START essentialcontacts_v1_generated_EssentialContactsService_ListContacts_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/essential_contacts_service.send_test_message.js b/samples/generated/v1/essential_contacts_service.send_test_message.js
index 122460f..64e2c8d 100644
--- a/samples/generated/v1/essential_contacts_service.send_test_message.js
+++ b/samples/generated/v1/essential_contacts_service.send_test_message.js
@@ -23,6 +23,9 @@
 function main(contacts, resource, notificationCategory) {
   // [START essentialcontacts_v1_generated_EssentialContactsService_SendTestMessage_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/essential_contacts_service.update_contact.js b/samples/generated/v1/essential_contacts_service.update_contact.js
index c81be34..92ad817 100644
--- a/samples/generated/v1/essential_contacts_service.update_contact.js
+++ b/samples/generated/v1/essential_contacts_service.update_contact.js
@@ -23,6 +23,9 @@
 function main(contact) {
   // [START essentialcontacts_v1_generated_EssentialContactsService_UpdateContact_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/snippet_metadata.google.cloud.essentialcontacts.v1.json b/samples/generated/v1/snippet_metadata.google.cloud.essentialcontacts.v1.json
index 8b33462..9613365 100644
--- a/samples/generated/v1/snippet_metadata.google.cloud.essentialcontacts.v1.json
+++ b/samples/generated/v1/snippet_metadata.google.cloud.essentialcontacts.v1.json
@@ -22,7 +22,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 58,
+                    "end": 61,
                     "type": "FULL"
                 }
             ],
@@ -66,7 +66,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 57,
+                    "end": 60,
                     "type": "FULL"
                 }
             ],
@@ -110,7 +110,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 68,
+                    "end": 71,
                     "type": "FULL"
                 }
             ],
@@ -158,7 +158,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 53,
+                    "end": 56,
                     "type": "FULL"
                 }
             ],
@@ -198,7 +198,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 53,
+                    "end": 56,
                     "type": "FULL"
                 }
             ],
@@ -238,7 +238,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 74,
+                    "end": 77,
                     "type": "FULL"
                 }
             ],
@@ -290,7 +290,7 @@
             "segments": [
                 {
                     "start": 25,
-                    "end": 68,
+                    "end": 71,
                     "type": "FULL"
                 }
             ],
diff --git a/src/v1/essential_contacts_service_client.ts b/src/v1/essential_contacts_service_client.ts
index 6a1b1b7..3ee4db1 100644
--- a/src/v1/essential_contacts_service_client.ts
+++ b/src/v1/essential_contacts_service_client.ts
@@ -28,7 +28,6 @@ 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');
 /**
@@ -272,7 +271,8 @@ export class EssentialContactsServiceClient {
       const apiCall = this._gaxModule.createApiCall(
         callPromise,
         this._defaults[methodName],
-        descriptor
+        descriptor,
+        this._opts.fallback
       );
 
       this.innerApiCalls[methodName] = apiCall;
@@ -997,7 +997,7 @@ export class EssentialContactsServiceClient {
     const callSettings = defaultCallSettings.merge(options);
     this.initialize();
     return this.descriptors.page.listContacts.createStream(
-      this.innerApiCalls.listContacts as gax.GaxCall,
+      this.innerApiCalls.listContacts as GaxCall,
       request,
       callSettings
     );
@@ -1053,7 +1053,7 @@ export class EssentialContactsServiceClient {
     this.initialize();
     return this.descriptors.page.listContacts.asyncIterate(
       this.innerApiCalls['listContacts'] as GaxCall,
-      request as unknown as RequestType,
+      request as {},
       callSettings
     ) as AsyncIterable<protos.google.cloud.essentialcontacts.v1.IContact>;
   }
@@ -1220,7 +1220,7 @@ export class EssentialContactsServiceClient {
     const callSettings = defaultCallSettings.merge(options);
     this.initialize();
     return this.descriptors.page.computeContacts.createStream(
-      this.innerApiCalls.computeContacts as gax.GaxCall,
+      this.innerApiCalls.computeContacts as GaxCall,
       request,
       callSettings
     );
@@ -1280,7 +1280,7 @@ export class EssentialContactsServiceClient {
     this.initialize();
     return this.descriptors.page.computeContacts.asyncIterate(
       this.innerApiCalls['computeContacts'] as GaxCall,
-      request as unknown as RequestType,
+      request as {},
       callSettings
     ) as AsyncIterable<protos.google.cloud.essentialcontacts.v1.IContact>;
   }
diff --git a/test/gapic_essential_contacts_service_v1.ts b/test/gapic_essential_contacts_service_v1.ts
index 1b3d957..07484d8 100644
--- a/test/gapic_essential_contacts_service_v1.ts
+++ b/test/gapic_essential_contacts_service_v1.ts
@@ -113,111 +113,113 @@ function stubAsyncIterationCall<ResponseType>(
 }
 
 describe('v1.EssentialContactsServiceClient', () => {
-  it('has servicePath', () => {
-    const servicePath =
-      essentialcontactsserviceModule.v1.EssentialContactsServiceClient
-        .servicePath;
-    assert(servicePath);
-  });
+  describe('Common methods', () => {
+    it('has servicePath', () => {
+      const servicePath =
+        essentialcontactsserviceModule.v1.EssentialContactsServiceClient
+          .servicePath;
+      assert(servicePath);
+    });
 
-  it('has apiEndpoint', () => {
-    const apiEndpoint =
-      essentialcontactsserviceModule.v1.EssentialContactsServiceClient
-        .apiEndpoint;
-    assert(apiEndpoint);
-  });
+    it('has apiEndpoint', () => {
+      const apiEndpoint =
+        essentialcontactsserviceModule.v1.EssentialContactsServiceClient
+          .apiEndpoint;
+      assert(apiEndpoint);
+    });
 
-  it('has port', () => {
-    const port =
-      essentialcontactsserviceModule.v1.EssentialContactsServiceClient.port;
-    assert(port);
-    assert(typeof port === 'number');
-  });
+    it('has port', () => {
+      const port =
+        essentialcontactsserviceModule.v1.EssentialContactsServiceClient.port;
+      assert(port);
+      assert(typeof port === 'number');
+    });
 
-  it('should create a client with no option', () => {
-    const client =
-      new essentialcontactsserviceModule.v1.EssentialContactsServiceClient();
-    assert(client);
-  });
+    it('should create a client with no option', () => {
+      const client =
+        new essentialcontactsserviceModule.v1.EssentialContactsServiceClient();
+      assert(client);
+    });
 
-  it('should create a client with gRPC fallback', () => {
-    const client =
-      new essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
-        fallback: true,
-      });
-    assert(client);
-  });
+    it('should create a client with gRPC fallback', () => {
+      const client =
+        new essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
+          fallback: true,
+        });
+      assert(client);
+    });
 
-  it('has initialize method and supports deferred initialization', async () => {
-    const client =
-      new essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
-      });
-    assert.strictEqual(client.essentialContactsServiceStub, undefined);
-    await client.initialize();
-    assert(client.essentialContactsServiceStub);
-  });
+    it('has initialize method and supports deferred initialization', async () => {
+      const client =
+        new essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      assert.strictEqual(client.essentialContactsServiceStub, undefined);
+      await client.initialize();
+      assert(client.essentialContactsServiceStub);
+    });
 
-  it('has close method for the initialized client', done => {
-    const client =
-      new essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
+    it('has close method for the initialized client', done => {
+      const client =
+        new essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      client.initialize();
+      assert(client.essentialContactsServiceStub);
+      client.close().then(() => {
+        done();
       });
-    client.initialize();
-    assert(client.essentialContactsServiceStub);
-    client.close().then(() => {
-      done();
     });
-  });
 
-  it('has close method for the non-initialized client', done => {
-    const client =
-      new essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
-        credentials: {client_email: 'bogus', private_key: 'bogus'},
-        projectId: 'bogus',
+    it('has close method for the non-initialized client', done => {
+      const client =
+        new essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
+          credentials: {client_email: 'bogus', private_key: 'bogus'},
+          projectId: 'bogus',
+        });
+      assert.strictEqual(client.essentialContactsServiceStub, undefined);
+      client.close().then(() => {
+        done();
       });
-    assert.strictEqual(client.essentialContactsServiceStub, undefined);
-    client.close().then(() => {
-      done();
     });
-  });
 
-  it('has getProjectId method', async () => {
-    const fakeProjectId = 'fake-project-id';
-    const client =
-      new essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
-        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 essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
+          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 essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
-        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 essentialcontactsserviceModule.v1.EssentialContactsServiceClient({
+          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('createContact', () => {