diff --git a/packages/google-cloud-automl/linkinator.config.json b/packages/google-cloud-automl/linkinator.config.json
index af4fa72352d..471cb1eadfd 100644
--- a/packages/google-cloud-automl/linkinator.config.json
+++ b/packages/google-cloud-automl/linkinator.config.json
@@ -5,5 +5,7 @@
     "https://codecov.io/gh/googleapis/",
     "www.googleapis.com",
     "img.shields.io"
-  ]
+  ],
+  "silent": true,
+  "concurrency": 10
 }
diff --git a/packages/google-cloud-automl/src/v1/auto_ml_client.ts b/packages/google-cloud-automl/src/v1/auto_ml_client.ts
index 5b12a04e732..c1c801af809 100644
--- a/packages/google-cloud-automl/src/v1/auto_ml_client.ts
+++ b/packages/google-cloud-automl/src/v1/auto_ml_client.ts
@@ -58,9 +58,14 @@ export class AutoMlClient {
   private _innerApiCalls: {[name: string]: Function};
   private _pathTemplates: {[name: string]: gax.PathTemplate};
   private _terminated = false;
+  private _opts: ClientOptions;
+  private _gaxModule: typeof gax | typeof gax.fallback;
+  private _gaxGrpc: gax.GrpcClient | gax.fallback.GrpcClient;
+  private _protos: {};
+  private _defaults: {[method: string]: gax.CallSettings};
   auth: gax.GoogleAuth;
   operationsClient: gax.OperationsClient;
-  autoMlStub: Promise<{[name: string]: Function}>;
+  autoMlStub?: Promise<{[name: string]: Function}>;
 
   /**
    * Construct an instance of AutoMlClient.
@@ -84,8 +89,6 @@ export class AutoMlClient {
    *     app is running in an environment which supports
    *     {@link https://developers.google.com/identity/protocols/application-default-credentials Application Default Credentials},
    *     your project ID will be detected automatically.
-   * @param {function} [options.promise] - Custom promise module to use instead
-   *     of native Promises.
    * @param {string} [options.apiEndpoint] - The domain name of the
    *     API remote host.
    */
@@ -115,25 +118,28 @@ export class AutoMlClient {
     // If we are in browser, we are already using fallback because of the
     // "browser" field in package.json.
     // But if we were explicitly requested to use fallback, let's do it now.
-    const gaxModule = !isBrowser && opts.fallback ? gax.fallback : gax;
+    this._gaxModule = !isBrowser && opts.fallback ? gax.fallback : gax;
 
     // Create a `gaxGrpc` object, with any grpc-specific options
     // sent to the client.
     opts.scopes = (this.constructor as typeof AutoMlClient).scopes;
-    const gaxGrpc = new gaxModule.GrpcClient(opts);
+    this._gaxGrpc = new this._gaxModule.GrpcClient(opts);
+
+    // Save options to use in initialize() method.
+    this._opts = opts;
 
     // Save the auth object to the client, for use by other methods.
-    this.auth = gaxGrpc.auth as gax.GoogleAuth;
+    this.auth = this._gaxGrpc.auth as gax.GoogleAuth;
 
     // Determine the client header string.
-    const clientHeader = [`gax/${gaxModule.version}`, `gapic/${version}`];
+    const clientHeader = [`gax/${this._gaxModule.version}`, `gapic/${version}`];
     if (typeof process !== 'undefined' && 'versions' in process) {
       clientHeader.push(`gl-node/${process.versions.node}`);
     } else {
-      clientHeader.push(`gl-web/${gaxModule.version}`);
+      clientHeader.push(`gl-web/${this._gaxModule.version}`);
     }
     if (!opts.fallback) {
-      clientHeader.push(`grpc/${gaxGrpc.grpcVersion}`);
+      clientHeader.push(`grpc/${this._gaxGrpc.grpcVersion}`);
     }
     if (opts.libName && opts.libVersion) {
       clientHeader.push(`${opts.libName}/${opts.libVersion}`);
@@ -149,7 +155,7 @@ export class AutoMlClient {
       'protos',
       'protos.json'
     );
-    const protos = gaxGrpc.loadProto(
+    this._protos = this._gaxGrpc.loadProto(
       opts.fallback ? require('../../protos/protos.json') : nodejsProtoPath
     );
 
@@ -157,19 +163,19 @@ export class AutoMlClient {
     // identifiers to uniquely identify resources within the API.
     // Create useful helper objects for these.
     this._pathTemplates = {
-      annotationSpecPathTemplate: new gaxModule.PathTemplate(
+      annotationSpecPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}/annotationSpecs/{annotation_spec}'
       ),
-      datasetPathTemplate: new gaxModule.PathTemplate(
+      datasetPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}'
       ),
-      locationPathTemplate: new gaxModule.PathTemplate(
+      locationPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}'
       ),
-      modelPathTemplate: new gaxModule.PathTemplate(
+      modelPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/models/{model}'
       ),
-      modelEvaluationPathTemplate: new gaxModule.PathTemplate(
+      modelEvaluationPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/models/{model}/modelEvaluations/{model_evaluation}'
       ),
     };
@@ -178,17 +184,17 @@ export class AutoMlClient {
     // (e.g. 50 results at a time, with tokens to get subsequent
     // pages). Denote the keys used for pagination and results.
     this._descriptors.page = {
-      listDatasets: new gaxModule.PageDescriptor(
+      listDatasets: new this._gaxModule.PageDescriptor(
         'pageToken',
         'nextPageToken',
         'datasets'
       ),
-      listModels: new gaxModule.PageDescriptor(
+      listModels: new this._gaxModule.PageDescriptor(
         'pageToken',
         'nextPageToken',
         'model'
       ),
-      listModelEvaluations: new gaxModule.PageDescriptor(
+      listModelEvaluations: new this._gaxModule.PageDescriptor(
         'pageToken',
         'nextPageToken',
         'modelEvaluation'
@@ -199,13 +205,15 @@ export class AutoMlClient {
     // an Operation object that allows for tracking of the operation,
     // rather than holding a request open.
     const protoFilesRoot = opts.fallback
-      ? gaxModule.protobuf.Root.fromJSON(require('../../protos/protos.json'))
-      : gaxModule.protobuf.loadSync(nodejsProtoPath);
+      ? this._gaxModule.protobuf.Root.fromJSON(
+          require('../../protos/protos.json')
+        )
+      : this._gaxModule.protobuf.loadSync(nodejsProtoPath);
 
-    this.operationsClient = gaxModule
+    this.operationsClient = this._gaxModule
       .lro({
         auth: this.auth,
-        grpc: 'grpc' in gaxGrpc ? gaxGrpc.grpc : undefined,
+        grpc: 'grpc' in this._gaxGrpc ? this._gaxGrpc.grpc : undefined,
       })
       .operationsClient(opts);
     const createDatasetResponse = protoFilesRoot.lookup(
@@ -264,47 +272,47 @@ export class AutoMlClient {
     ) as gax.protobuf.Type;
 
     this._descriptors.longrunning = {
-      createDataset: new gaxModule.LongrunningDescriptor(
+      createDataset: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         createDatasetResponse.decode.bind(createDatasetResponse),
         createDatasetMetadata.decode.bind(createDatasetMetadata)
       ),
-      deleteDataset: new gaxModule.LongrunningDescriptor(
+      deleteDataset: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         deleteDatasetResponse.decode.bind(deleteDatasetResponse),
         deleteDatasetMetadata.decode.bind(deleteDatasetMetadata)
       ),
-      importData: new gaxModule.LongrunningDescriptor(
+      importData: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         importDataResponse.decode.bind(importDataResponse),
         importDataMetadata.decode.bind(importDataMetadata)
       ),
-      exportData: new gaxModule.LongrunningDescriptor(
+      exportData: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         exportDataResponse.decode.bind(exportDataResponse),
         exportDataMetadata.decode.bind(exportDataMetadata)
       ),
-      createModel: new gaxModule.LongrunningDescriptor(
+      createModel: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         createModelResponse.decode.bind(createModelResponse),
         createModelMetadata.decode.bind(createModelMetadata)
       ),
-      deleteModel: new gaxModule.LongrunningDescriptor(
+      deleteModel: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         deleteModelResponse.decode.bind(deleteModelResponse),
         deleteModelMetadata.decode.bind(deleteModelMetadata)
       ),
-      deployModel: new gaxModule.LongrunningDescriptor(
+      deployModel: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         deployModelResponse.decode.bind(deployModelResponse),
         deployModelMetadata.decode.bind(deployModelMetadata)
       ),
-      undeployModel: new gaxModule.LongrunningDescriptor(
+      undeployModel: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         undeployModelResponse.decode.bind(undeployModelResponse),
         undeployModelMetadata.decode.bind(undeployModelMetadata)
       ),
-      exportModel: new gaxModule.LongrunningDescriptor(
+      exportModel: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         exportModelResponse.decode.bind(exportModelResponse),
         exportModelMetadata.decode.bind(exportModelMetadata)
@@ -312,7 +320,7 @@ export class AutoMlClient {
     };
 
     // Put together the default options sent with requests.
-    const defaults = gaxGrpc.constructSettings(
+    this._defaults = this._gaxGrpc.constructSettings(
       'google.cloud.automl.v1.AutoMl',
       gapicConfig as gax.ClientConfig,
       opts.clientConfig || {},
@@ -323,17 +331,35 @@ export class AutoMlClient {
     // of calling the API is handled in `google-gax`, with this code
     // merely providing the destination and request information.
     this._innerApiCalls = {};
+  }
+
+  /**
+   * Initialize the client.
+   * Performs asynchronous operations (such as authentication) and prepares the client.
+   * This function will be called automatically when any class method is called for the
+   * first time, but if you need to initialize it before calling an actual method,
+   * feel free to call initialize() directly.
+   *
+   * You can await on this method if you want to make sure the client is initialized.
+   *
+   * @returns {Promise} A promise that resolves to an authenticated service stub.
+   */
+  initialize() {
+    // If the client stub promise is already initialized, return immediately.
+    if (this.autoMlStub) {
+      return this.autoMlStub;
+    }
 
     // Put together the "service stub" for
     // google.cloud.automl.v1.AutoMl.
-    this.autoMlStub = gaxGrpc.createStub(
-      opts.fallback
-        ? (protos as protobuf.Root).lookupService(
+    this.autoMlStub = this._gaxGrpc.createStub(
+      this._opts.fallback
+        ? (this._protos as protobuf.Root).lookupService(
             'google.cloud.automl.v1.AutoMl'
           )
         : // tslint:disable-next-line no-any
-          (protos as any).google.cloud.automl.v1.AutoMl,
-      opts
+          (this._protos as any).google.cloud.automl.v1.AutoMl,
+      this._opts
     ) as Promise<{[method: string]: Function}>;
 
     // Iterate over each of the methods that the service provides
@@ -372,9 +398,9 @@ export class AutoMlClient {
         }
       );
 
-      const apiCall = gaxModule.createApiCall(
+      const apiCall = this._gaxModule.createApiCall(
         innerCallPromise,
-        defaults[methodName],
+        this._defaults[methodName],
         this._descriptors.page[methodName] ||
           this._descriptors.stream[methodName] ||
           this._descriptors.longrunning[methodName]
@@ -388,6 +414,8 @@ export class AutoMlClient {
         return apiCall(argument, callOptions, callback);
       };
     }
+
+    return this.autoMlStub;
   }
 
   /**
@@ -509,6 +537,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.getDataset(request, options, callback);
   }
   updateDataset(
@@ -582,6 +611,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       'dataset.name': request.dataset!.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.updateDataset(request, options, callback);
   }
   getAnnotationSpec(
@@ -654,6 +684,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.getAnnotationSpec(request, options, callback);
   }
   getModel(
@@ -725,6 +756,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.getModel(request, options, callback);
   }
   updateModel(
@@ -798,6 +830,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       'model.name': request.model!.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.updateModel(request, options, callback);
   }
   getModelEvaluation(
@@ -870,6 +903,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.getModelEvaluation(request, options, callback);
   }
 
@@ -959,6 +993,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.createDataset(request, options, callback);
   }
   deleteDataset(
@@ -989,9 +1024,9 @@ export class AutoMlClient {
   /**
    * Deletes a dataset and all of its contents.
    * Returns empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes,
+   * {@link google.longrunning.Operation.response|response} field when it completes,
    * and `delete_details` in the
-   * [metadata][google.longrunning.Operation.metadata] field.
+   * {@link google.longrunning.Operation.metadata|metadata} field.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1049,6 +1084,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.deleteDataset(request, options, callback);
   }
   importData(
@@ -1082,10 +1118,10 @@ export class AutoMlClient {
    *
    * For Tables:
    * *   A
-   * [schema_inference_version][google.cloud.automl.v1.InputConfig.params]
+   * {@link google.cloud.automl.v1.InputConfig.params|schema_inference_version}
    *     parameter must be explicitly set.
    * Returns an empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes.
+   * {@link google.longrunning.Operation.response|response} field when it completes.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1147,6 +1183,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.importData(request, options, callback);
   }
   exportData(
@@ -1177,7 +1214,7 @@ export class AutoMlClient {
   /**
    * Exports dataset's data to the provided output location.
    * Returns an empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes.
+   * {@link google.longrunning.Operation.response|response} field when it completes.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1237,6 +1274,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.exportData(request, options, callback);
   }
   createModel(
@@ -1266,7 +1304,7 @@ export class AutoMlClient {
   ): void;
   /**
    * Creates a model.
-   * Returns a Model in the [response][google.longrunning.Operation.response]
+   * Returns a Model in the {@link google.longrunning.Operation.response|response}
    * field when it completes.
    * When you create a model, several model evaluations are created for it:
    * a global evaluation, and one evaluation for each annotation spec.
@@ -1329,6 +1367,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.createModel(request, options, callback);
   }
   deleteModel(
@@ -1359,9 +1398,9 @@ export class AutoMlClient {
   /**
    * Deletes a model.
    * Returns `google.protobuf.Empty` in the
-   * [response][google.longrunning.Operation.response] field when it completes,
+   * {@link google.longrunning.Operation.response|response} field when it completes,
    * and `delete_details` in the
-   * [metadata][google.longrunning.Operation.metadata] field.
+   * {@link google.longrunning.Operation.metadata|metadata} field.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1419,6 +1458,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.deleteModel(request, options, callback);
   }
   deployModel(
@@ -1451,14 +1491,14 @@ export class AutoMlClient {
    * same parameters has no effect. Deploying with different parametrs
    * (as e.g. changing
    *
-   * [node_number][google.cloud.automl.v1p1beta.ImageObjectDetectionModelDeploymentMetadata.node_number])
+   * {@link google.cloud.automl.v1p1beta.ImageObjectDetectionModelDeploymentMetadata.node_number|node_number})
    *  will reset the deployment state without pausing the model's availability.
    *
    * Only applicable for Text Classification, Image Object Detection , Tables, and Image Segmentation; all other domains manage
    * deployment automatically.
    *
    * Returns an empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes.
+   * {@link google.longrunning.Operation.response|response} field when it completes.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1520,6 +1560,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.deployModel(request, options, callback);
   }
   undeployModel(
@@ -1554,7 +1595,7 @@ export class AutoMlClient {
    * all other domains manage deployment automatically.
    *
    * Returns an empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes.
+   * {@link google.longrunning.Operation.response|response} field when it completes.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1612,6 +1653,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.undeployModel(request, options, callback);
   }
   exportModel(
@@ -1643,10 +1685,10 @@ export class AutoMlClient {
    * Exports a trained, "export-able", model to a user specified Google Cloud
    * Storage location. A model is considered export-able if and only if it has
    * an export format defined for it in
-   * [ModelExportOutputConfig][google.cloud.automl.v1.ModelExportOutputConfig].
+   * {@link google.cloud.automl.v1.ModelExportOutputConfig|ModelExportOutputConfig}.
    *
    * Returns an empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes.
+   * {@link google.longrunning.Operation.response|response} field when it completes.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1706,6 +1748,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.exportModel(request, options, callback);
   }
   listDatasets(
@@ -1748,8 +1791,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return
    *   Typically obtained via
-   *   [ListDatasetsResponse.next_page_token][google.cloud.automl.v1.ListDatasetsResponse.next_page_token] of the previous
-   *   [AutoMl.ListDatasets][google.cloud.automl.v1.AutoMl.ListDatasets] call.
+   *   {@link google.cloud.automl.v1.ListDatasetsResponse.next_page_token|ListDatasetsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1.AutoMl.ListDatasets|AutoMl.ListDatasets} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Promise} - The promise which resolves to an array.
@@ -1805,6 +1848,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.listDatasets(request, options, callback);
   }
 
@@ -1839,8 +1883,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return
    *   Typically obtained via
-   *   [ListDatasetsResponse.next_page_token][google.cloud.automl.v1.ListDatasetsResponse.next_page_token] of the previous
-   *   [AutoMl.ListDatasets][google.cloud.automl.v1.AutoMl.ListDatasets] call.
+   *   {@link google.cloud.automl.v1.ListDatasetsResponse.next_page_token|ListDatasetsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1.AutoMl.ListDatasets|AutoMl.ListDatasets} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Stream}
@@ -1860,6 +1904,7 @@ export class AutoMlClient {
       parent: request.parent || '',
     });
     const callSettings = new gax.CallSettings(options);
+    this.initialize();
     return this._descriptors.page.listDatasets.createStream(
       this._innerApiCalls.listDatasets as gax.GaxCall,
       request,
@@ -1907,8 +1952,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return
    *   Typically obtained via
-   *   [ListModelsResponse.next_page_token][google.cloud.automl.v1.ListModelsResponse.next_page_token] of the previous
-   *   [AutoMl.ListModels][google.cloud.automl.v1.AutoMl.ListModels] call.
+   *   {@link google.cloud.automl.v1.ListModelsResponse.next_page_token|ListModelsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1.AutoMl.ListModels|AutoMl.ListModels} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Promise} - The promise which resolves to an array.
@@ -1964,6 +2009,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.listModels(request, options, callback);
   }
 
@@ -1999,8 +2045,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return
    *   Typically obtained via
-   *   [ListModelsResponse.next_page_token][google.cloud.automl.v1.ListModelsResponse.next_page_token] of the previous
-   *   [AutoMl.ListModels][google.cloud.automl.v1.AutoMl.ListModels] call.
+   *   {@link google.cloud.automl.v1.ListModelsResponse.next_page_token|ListModelsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1.AutoMl.ListModels|AutoMl.ListModels} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Stream}
@@ -2020,6 +2066,7 @@ export class AutoMlClient {
       parent: request.parent || '',
     });
     const callSettings = new gax.CallSettings(options);
+    this.initialize();
     return this._descriptors.page.listModels.createStream(
       this._innerApiCalls.listModels as gax.GaxCall,
       request,
@@ -2071,8 +2118,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return.
    *   Typically obtained via
-   *   [ListModelEvaluationsResponse.next_page_token][google.cloud.automl.v1.ListModelEvaluationsResponse.next_page_token] of the previous
-   *   [AutoMl.ListModelEvaluations][google.cloud.automl.v1.AutoMl.ListModelEvaluations] call.
+   *   {@link google.cloud.automl.v1.ListModelEvaluationsResponse.next_page_token|ListModelEvaluationsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1.AutoMl.ListModelEvaluations|AutoMl.ListModelEvaluations} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Promise} - The promise which resolves to an array.
@@ -2128,6 +2175,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.listModelEvaluations(request, options, callback);
   }
 
@@ -2167,8 +2215,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return.
    *   Typically obtained via
-   *   [ListModelEvaluationsResponse.next_page_token][google.cloud.automl.v1.ListModelEvaluationsResponse.next_page_token] of the previous
-   *   [AutoMl.ListModelEvaluations][google.cloud.automl.v1.AutoMl.ListModelEvaluations] call.
+   *   {@link google.cloud.automl.v1.ListModelEvaluationsResponse.next_page_token|ListModelEvaluationsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1.AutoMl.ListModelEvaluations|AutoMl.ListModelEvaluations} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Stream}
@@ -2188,6 +2236,7 @@ export class AutoMlClient {
       parent: request.parent || '',
     });
     const callSettings = new gax.CallSettings(options);
+    this.initialize();
     return this._descriptors.page.listModelEvaluations.createStream(
       this._innerApiCalls.listModelEvaluations as gax.GaxCall,
       request,
@@ -2489,8 +2538,9 @@ export class AutoMlClient {
    * The client will no longer be usable and all future behavior is undefined.
    */
   close(): Promise<void> {
+    this.initialize();
     if (!this._terminated) {
-      return this.autoMlStub.then(stub => {
+      return this.autoMlStub!.then(stub => {
         this._terminated = true;
         stub.close();
       });
diff --git a/packages/google-cloud-automl/src/v1/prediction_service_client.ts b/packages/google-cloud-automl/src/v1/prediction_service_client.ts
index d3bcf5674dd..515ce3c2f1f 100644
--- a/packages/google-cloud-automl/src/v1/prediction_service_client.ts
+++ b/packages/google-cloud-automl/src/v1/prediction_service_client.ts
@@ -45,9 +45,14 @@ export class PredictionServiceClient {
   private _innerApiCalls: {[name: string]: Function};
   private _pathTemplates: {[name: string]: gax.PathTemplate};
   private _terminated = false;
+  private _opts: ClientOptions;
+  private _gaxModule: typeof gax | typeof gax.fallback;
+  private _gaxGrpc: gax.GrpcClient | gax.fallback.GrpcClient;
+  private _protos: {};
+  private _defaults: {[method: string]: gax.CallSettings};
   auth: gax.GoogleAuth;
   operationsClient: gax.OperationsClient;
-  predictionServiceStub: Promise<{[name: string]: Function}>;
+  predictionServiceStub?: Promise<{[name: string]: Function}>;
 
   /**
    * Construct an instance of PredictionServiceClient.
@@ -71,8 +76,6 @@ export class PredictionServiceClient {
    *     app is running in an environment which supports
    *     {@link https://developers.google.com/identity/protocols/application-default-credentials Application Default Credentials},
    *     your project ID will be detected automatically.
-   * @param {function} [options.promise] - Custom promise module to use instead
-   *     of native Promises.
    * @param {string} [options.apiEndpoint] - The domain name of the
    *     API remote host.
    */
@@ -102,25 +105,28 @@ export class PredictionServiceClient {
     // If we are in browser, we are already using fallback because of the
     // "browser" field in package.json.
     // But if we were explicitly requested to use fallback, let's do it now.
-    const gaxModule = !isBrowser && opts.fallback ? gax.fallback : gax;
+    this._gaxModule = !isBrowser && opts.fallback ? gax.fallback : gax;
 
     // Create a `gaxGrpc` object, with any grpc-specific options
     // sent to the client.
     opts.scopes = (this.constructor as typeof PredictionServiceClient).scopes;
-    const gaxGrpc = new gaxModule.GrpcClient(opts);
+    this._gaxGrpc = new this._gaxModule.GrpcClient(opts);
+
+    // Save options to use in initialize() method.
+    this._opts = opts;
 
     // Save the auth object to the client, for use by other methods.
-    this.auth = gaxGrpc.auth as gax.GoogleAuth;
+    this.auth = this._gaxGrpc.auth as gax.GoogleAuth;
 
     // Determine the client header string.
-    const clientHeader = [`gax/${gaxModule.version}`, `gapic/${version}`];
+    const clientHeader = [`gax/${this._gaxModule.version}`, `gapic/${version}`];
     if (typeof process !== 'undefined' && 'versions' in process) {
       clientHeader.push(`gl-node/${process.versions.node}`);
     } else {
-      clientHeader.push(`gl-web/${gaxModule.version}`);
+      clientHeader.push(`gl-web/${this._gaxModule.version}`);
     }
     if (!opts.fallback) {
-      clientHeader.push(`grpc/${gaxGrpc.grpcVersion}`);
+      clientHeader.push(`grpc/${this._gaxGrpc.grpcVersion}`);
     }
     if (opts.libName && opts.libVersion) {
       clientHeader.push(`${opts.libName}/${opts.libVersion}`);
@@ -136,7 +142,7 @@ export class PredictionServiceClient {
       'protos',
       'protos.json'
     );
-    const protos = gaxGrpc.loadProto(
+    this._protos = this._gaxGrpc.loadProto(
       opts.fallback ? require('../../protos/protos.json') : nodejsProtoPath
     );
 
@@ -144,16 +150,16 @@ export class PredictionServiceClient {
     // identifiers to uniquely identify resources within the API.
     // Create useful helper objects for these.
     this._pathTemplates = {
-      annotationSpecPathTemplate: new gaxModule.PathTemplate(
+      annotationSpecPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}/annotationSpecs/{annotation_spec}'
       ),
-      datasetPathTemplate: new gaxModule.PathTemplate(
+      datasetPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}'
       ),
-      modelPathTemplate: new gaxModule.PathTemplate(
+      modelPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/models/{model}'
       ),
-      modelEvaluationPathTemplate: new gaxModule.PathTemplate(
+      modelEvaluationPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/models/{model}/modelEvaluations/{model_evaluation}'
       ),
     };
@@ -162,13 +168,15 @@ export class PredictionServiceClient {
     // an Operation object that allows for tracking of the operation,
     // rather than holding a request open.
     const protoFilesRoot = opts.fallback
-      ? gaxModule.protobuf.Root.fromJSON(require('../../protos/protos.json'))
-      : gaxModule.protobuf.loadSync(nodejsProtoPath);
+      ? this._gaxModule.protobuf.Root.fromJSON(
+          require('../../protos/protos.json')
+        )
+      : this._gaxModule.protobuf.loadSync(nodejsProtoPath);
 
-    this.operationsClient = gaxModule
+    this.operationsClient = this._gaxModule
       .lro({
         auth: this.auth,
-        grpc: 'grpc' in gaxGrpc ? gaxGrpc.grpc : undefined,
+        grpc: 'grpc' in this._gaxGrpc ? this._gaxGrpc.grpc : undefined,
       })
       .operationsClient(opts);
     const batchPredictResponse = protoFilesRoot.lookup(
@@ -179,7 +187,7 @@ export class PredictionServiceClient {
     ) as gax.protobuf.Type;
 
     this._descriptors.longrunning = {
-      batchPredict: new gaxModule.LongrunningDescriptor(
+      batchPredict: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         batchPredictResponse.decode.bind(batchPredictResponse),
         batchPredictMetadata.decode.bind(batchPredictMetadata)
@@ -187,7 +195,7 @@ export class PredictionServiceClient {
     };
 
     // Put together the default options sent with requests.
-    const defaults = gaxGrpc.constructSettings(
+    this._defaults = this._gaxGrpc.constructSettings(
       'google.cloud.automl.v1.PredictionService',
       gapicConfig as gax.ClientConfig,
       opts.clientConfig || {},
@@ -198,17 +206,35 @@ export class PredictionServiceClient {
     // of calling the API is handled in `google-gax`, with this code
     // merely providing the destination and request information.
     this._innerApiCalls = {};
+  }
+
+  /**
+   * Initialize the client.
+   * Performs asynchronous operations (such as authentication) and prepares the client.
+   * This function will be called automatically when any class method is called for the
+   * first time, but if you need to initialize it before calling an actual method,
+   * feel free to call initialize() directly.
+   *
+   * You can await on this method if you want to make sure the client is initialized.
+   *
+   * @returns {Promise} A promise that resolves to an authenticated service stub.
+   */
+  initialize() {
+    // If the client stub promise is already initialized, return immediately.
+    if (this.predictionServiceStub) {
+      return this.predictionServiceStub;
+    }
 
     // Put together the "service stub" for
     // google.cloud.automl.v1.PredictionService.
-    this.predictionServiceStub = gaxGrpc.createStub(
-      opts.fallback
-        ? (protos as protobuf.Root).lookupService(
+    this.predictionServiceStub = this._gaxGrpc.createStub(
+      this._opts.fallback
+        ? (this._protos as protobuf.Root).lookupService(
             'google.cloud.automl.v1.PredictionService'
           )
         : // tslint:disable-next-line no-any
-          (protos as any).google.cloud.automl.v1.PredictionService,
-      opts
+          (this._protos as any).google.cloud.automl.v1.PredictionService,
+      this._opts
     ) as Promise<{[method: string]: Function}>;
 
     // Iterate over each of the methods that the service provides
@@ -228,9 +254,9 @@ export class PredictionServiceClient {
         }
       );
 
-      const apiCall = gaxModule.createApiCall(
+      const apiCall = this._gaxModule.createApiCall(
         innerCallPromise,
-        defaults[methodName],
+        this._defaults[methodName],
         this._descriptors.page[methodName] ||
           this._descriptors.stream[methodName] ||
           this._descriptors.longrunning[methodName]
@@ -244,6 +270,8 @@ export class PredictionServiceClient {
         return apiCall(argument, callOptions, callback);
       };
     }
+
+    return this.predictionServiceStub;
   }
 
   /**
@@ -392,9 +420,9 @@ export class PredictionServiceClient {
    *   `feature_importance`
    *   : (boolean) Whether
    *
-   *   [feature_importance][google.cloud.automl.v1.TablesModelColumnInfo.feature_importance]
+   *   {@link google.cloud.automl.v1.TablesModelColumnInfo.feature_importance|feature_importance}
    *     is populated in the returned list of
-   *     [TablesAnnotation][google.cloud.automl.v1.TablesAnnotation]
+   *     {@link google.cloud.automl.v1.TablesAnnotation|TablesAnnotation}
    *     objects. The default is false.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
@@ -439,6 +467,7 @@ export class PredictionServiceClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.predict(request, options, callback);
   }
 
@@ -468,12 +497,12 @@ export class PredictionServiceClient {
     >
   ): void;
   /**
-   * Perform a batch prediction. Unlike the online [Predict][google.cloud.automl.v1.PredictionService.Predict], batch
+   * Perform a batch prediction. Unlike the online {@link google.cloud.automl.v1.PredictionService.Predict|Predict}, batch
    * prediction result won't be immediately available in the response. Instead,
    * a long running operation object is returned. User can poll the operation
-   * result via [GetOperation][google.longrunning.Operations.GetOperation]
-   * method. Once the operation is done, [BatchPredictResult][google.cloud.automl.v1.BatchPredictResult] is returned in
-   * the [response][google.longrunning.Operation.response] field.
+   * result via {@link google.longrunning.Operations.GetOperation|GetOperation}
+   * method. Once the operation is done, {@link google.cloud.automl.v1.BatchPredictResult|BatchPredictResult} is returned in
+   * the {@link google.longrunning.Operation.response|response} field.
    * Available for following ML scenarios:
    *
    * * AutoML Vision Classification
@@ -630,6 +659,7 @@ export class PredictionServiceClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.batchPredict(request, options, callback);
   }
   // --------------------
@@ -890,8 +920,9 @@ export class PredictionServiceClient {
    * The client will no longer be usable and all future behavior is undefined.
    */
   close(): Promise<void> {
+    this.initialize();
     if (!this._terminated) {
-      return this.predictionServiceStub.then(stub => {
+      return this.predictionServiceStub!.then(stub => {
         this._terminated = true;
         stub.close();
       });
diff --git a/packages/google-cloud-automl/src/v1beta1/auto_ml_client.ts b/packages/google-cloud-automl/src/v1beta1/auto_ml_client.ts
index 0babf3e1909..13c6928e683 100644
--- a/packages/google-cloud-automl/src/v1beta1/auto_ml_client.ts
+++ b/packages/google-cloud-automl/src/v1beta1/auto_ml_client.ts
@@ -58,9 +58,14 @@ export class AutoMlClient {
   private _innerApiCalls: {[name: string]: Function};
   private _pathTemplates: {[name: string]: gax.PathTemplate};
   private _terminated = false;
+  private _opts: ClientOptions;
+  private _gaxModule: typeof gax | typeof gax.fallback;
+  private _gaxGrpc: gax.GrpcClient | gax.fallback.GrpcClient;
+  private _protos: {};
+  private _defaults: {[method: string]: gax.CallSettings};
   auth: gax.GoogleAuth;
   operationsClient: gax.OperationsClient;
-  autoMlStub: Promise<{[name: string]: Function}>;
+  autoMlStub?: Promise<{[name: string]: Function}>;
 
   /**
    * Construct an instance of AutoMlClient.
@@ -84,8 +89,6 @@ export class AutoMlClient {
    *     app is running in an environment which supports
    *     {@link https://developers.google.com/identity/protocols/application-default-credentials Application Default Credentials},
    *     your project ID will be detected automatically.
-   * @param {function} [options.promise] - Custom promise module to use instead
-   *     of native Promises.
    * @param {string} [options.apiEndpoint] - The domain name of the
    *     API remote host.
    */
@@ -115,25 +118,28 @@ export class AutoMlClient {
     // If we are in browser, we are already using fallback because of the
     // "browser" field in package.json.
     // But if we were explicitly requested to use fallback, let's do it now.
-    const gaxModule = !isBrowser && opts.fallback ? gax.fallback : gax;
+    this._gaxModule = !isBrowser && opts.fallback ? gax.fallback : gax;
 
     // Create a `gaxGrpc` object, with any grpc-specific options
     // sent to the client.
     opts.scopes = (this.constructor as typeof AutoMlClient).scopes;
-    const gaxGrpc = new gaxModule.GrpcClient(opts);
+    this._gaxGrpc = new this._gaxModule.GrpcClient(opts);
+
+    // Save options to use in initialize() method.
+    this._opts = opts;
 
     // Save the auth object to the client, for use by other methods.
-    this.auth = gaxGrpc.auth as gax.GoogleAuth;
+    this.auth = this._gaxGrpc.auth as gax.GoogleAuth;
 
     // Determine the client header string.
-    const clientHeader = [`gax/${gaxModule.version}`, `gapic/${version}`];
+    const clientHeader = [`gax/${this._gaxModule.version}`, `gapic/${version}`];
     if (typeof process !== 'undefined' && 'versions' in process) {
       clientHeader.push(`gl-node/${process.versions.node}`);
     } else {
-      clientHeader.push(`gl-web/${gaxModule.version}`);
+      clientHeader.push(`gl-web/${this._gaxModule.version}`);
     }
     if (!opts.fallback) {
-      clientHeader.push(`grpc/${gaxGrpc.grpcVersion}`);
+      clientHeader.push(`grpc/${this._gaxGrpc.grpcVersion}`);
     }
     if (opts.libName && opts.libVersion) {
       clientHeader.push(`${opts.libName}/${opts.libVersion}`);
@@ -149,7 +155,7 @@ export class AutoMlClient {
       'protos',
       'protos.json'
     );
-    const protos = gaxGrpc.loadProto(
+    this._protos = this._gaxGrpc.loadProto(
       opts.fallback ? require('../../protos/protos.json') : nodejsProtoPath
     );
 
@@ -157,25 +163,25 @@ export class AutoMlClient {
     // identifiers to uniquely identify resources within the API.
     // Create useful helper objects for these.
     this._pathTemplates = {
-      annotationSpecPathTemplate: new gaxModule.PathTemplate(
+      annotationSpecPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}/annotationSpecs/{annotation_spec}'
       ),
-      columnSpecPathTemplate: new gaxModule.PathTemplate(
+      columnSpecPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}/tableSpecs/{table_spec}/columnSpecs/{column_spec}'
       ),
-      datasetPathTemplate: new gaxModule.PathTemplate(
+      datasetPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}'
       ),
-      locationPathTemplate: new gaxModule.PathTemplate(
+      locationPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}'
       ),
-      modelPathTemplate: new gaxModule.PathTemplate(
+      modelPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/models/{model}'
       ),
-      modelEvaluationPathTemplate: new gaxModule.PathTemplate(
+      modelEvaluationPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/models/{model}/modelEvaluations/{model_evaluation}'
       ),
-      tableSpecPathTemplate: new gaxModule.PathTemplate(
+      tableSpecPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}/tableSpecs/{table_spec}'
       ),
     };
@@ -184,27 +190,27 @@ export class AutoMlClient {
     // (e.g. 50 results at a time, with tokens to get subsequent
     // pages). Denote the keys used for pagination and results.
     this._descriptors.page = {
-      listDatasets: new gaxModule.PageDescriptor(
+      listDatasets: new this._gaxModule.PageDescriptor(
         'pageToken',
         'nextPageToken',
         'datasets'
       ),
-      listTableSpecs: new gaxModule.PageDescriptor(
+      listTableSpecs: new this._gaxModule.PageDescriptor(
         'pageToken',
         'nextPageToken',
         'tableSpecs'
       ),
-      listColumnSpecs: new gaxModule.PageDescriptor(
+      listColumnSpecs: new this._gaxModule.PageDescriptor(
         'pageToken',
         'nextPageToken',
         'columnSpecs'
       ),
-      listModels: new gaxModule.PageDescriptor(
+      listModels: new this._gaxModule.PageDescriptor(
         'pageToken',
         'nextPageToken',
         'model'
       ),
-      listModelEvaluations: new gaxModule.PageDescriptor(
+      listModelEvaluations: new this._gaxModule.PageDescriptor(
         'pageToken',
         'nextPageToken',
         'modelEvaluation'
@@ -215,13 +221,15 @@ export class AutoMlClient {
     // an Operation object that allows for tracking of the operation,
     // rather than holding a request open.
     const protoFilesRoot = opts.fallback
-      ? gaxModule.protobuf.Root.fromJSON(require('../../protos/protos.json'))
-      : gaxModule.protobuf.loadSync(nodejsProtoPath);
+      ? this._gaxModule.protobuf.Root.fromJSON(
+          require('../../protos/protos.json')
+        )
+      : this._gaxModule.protobuf.loadSync(nodejsProtoPath);
 
-    this.operationsClient = gaxModule
+    this.operationsClient = this._gaxModule
       .lro({
         auth: this.auth,
-        grpc: 'grpc' in gaxGrpc ? gaxGrpc.grpc : undefined,
+        grpc: 'grpc' in this._gaxGrpc ? this._gaxGrpc.grpc : undefined,
       })
       .operationsClient(opts);
     const deleteDatasetResponse = protoFilesRoot.lookup(
@@ -280,47 +288,47 @@ export class AutoMlClient {
     ) as gax.protobuf.Type;
 
     this._descriptors.longrunning = {
-      deleteDataset: new gaxModule.LongrunningDescriptor(
+      deleteDataset: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         deleteDatasetResponse.decode.bind(deleteDatasetResponse),
         deleteDatasetMetadata.decode.bind(deleteDatasetMetadata)
       ),
-      importData: new gaxModule.LongrunningDescriptor(
+      importData: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         importDataResponse.decode.bind(importDataResponse),
         importDataMetadata.decode.bind(importDataMetadata)
       ),
-      exportData: new gaxModule.LongrunningDescriptor(
+      exportData: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         exportDataResponse.decode.bind(exportDataResponse),
         exportDataMetadata.decode.bind(exportDataMetadata)
       ),
-      createModel: new gaxModule.LongrunningDescriptor(
+      createModel: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         createModelResponse.decode.bind(createModelResponse),
         createModelMetadata.decode.bind(createModelMetadata)
       ),
-      deleteModel: new gaxModule.LongrunningDescriptor(
+      deleteModel: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         deleteModelResponse.decode.bind(deleteModelResponse),
         deleteModelMetadata.decode.bind(deleteModelMetadata)
       ),
-      deployModel: new gaxModule.LongrunningDescriptor(
+      deployModel: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         deployModelResponse.decode.bind(deployModelResponse),
         deployModelMetadata.decode.bind(deployModelMetadata)
       ),
-      undeployModel: new gaxModule.LongrunningDescriptor(
+      undeployModel: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         undeployModelResponse.decode.bind(undeployModelResponse),
         undeployModelMetadata.decode.bind(undeployModelMetadata)
       ),
-      exportModel: new gaxModule.LongrunningDescriptor(
+      exportModel: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         exportModelResponse.decode.bind(exportModelResponse),
         exportModelMetadata.decode.bind(exportModelMetadata)
       ),
-      exportEvaluatedExamples: new gaxModule.LongrunningDescriptor(
+      exportEvaluatedExamples: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         exportEvaluatedExamplesResponse.decode.bind(
           exportEvaluatedExamplesResponse
@@ -332,7 +340,7 @@ export class AutoMlClient {
     };
 
     // Put together the default options sent with requests.
-    const defaults = gaxGrpc.constructSettings(
+    this._defaults = this._gaxGrpc.constructSettings(
       'google.cloud.automl.v1beta1.AutoMl',
       gapicConfig as gax.ClientConfig,
       opts.clientConfig || {},
@@ -343,17 +351,35 @@ export class AutoMlClient {
     // of calling the API is handled in `google-gax`, with this code
     // merely providing the destination and request information.
     this._innerApiCalls = {};
+  }
+
+  /**
+   * Initialize the client.
+   * Performs asynchronous operations (such as authentication) and prepares the client.
+   * This function will be called automatically when any class method is called for the
+   * first time, but if you need to initialize it before calling an actual method,
+   * feel free to call initialize() directly.
+   *
+   * You can await on this method if you want to make sure the client is initialized.
+   *
+   * @returns {Promise} A promise that resolves to an authenticated service stub.
+   */
+  initialize() {
+    // If the client stub promise is already initialized, return immediately.
+    if (this.autoMlStub) {
+      return this.autoMlStub;
+    }
 
     // Put together the "service stub" for
     // google.cloud.automl.v1beta1.AutoMl.
-    this.autoMlStub = gaxGrpc.createStub(
-      opts.fallback
-        ? (protos as protobuf.Root).lookupService(
+    this.autoMlStub = this._gaxGrpc.createStub(
+      this._opts.fallback
+        ? (this._protos as protobuf.Root).lookupService(
             'google.cloud.automl.v1beta1.AutoMl'
           )
         : // tslint:disable-next-line no-any
-          (protos as any).google.cloud.automl.v1beta1.AutoMl,
-      opts
+          (this._protos as any).google.cloud.automl.v1beta1.AutoMl,
+      this._opts
     ) as Promise<{[method: string]: Function}>;
 
     // Iterate over each of the methods that the service provides
@@ -398,9 +424,9 @@ export class AutoMlClient {
         }
       );
 
-      const apiCall = gaxModule.createApiCall(
+      const apiCall = this._gaxModule.createApiCall(
         innerCallPromise,
-        defaults[methodName],
+        this._defaults[methodName],
         this._descriptors.page[methodName] ||
           this._descriptors.stream[methodName] ||
           this._descriptors.longrunning[methodName]
@@ -414,6 +440,8 @@ export class AutoMlClient {
         return apiCall(argument, callOptions, callback);
       };
     }
+
+    return this.autoMlStub;
   }
 
   /**
@@ -538,6 +566,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.createDataset(request, options, callback);
   }
   getDataset(
@@ -610,6 +639,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.getDataset(request, options, callback);
   }
   updateDataset(
@@ -684,6 +714,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       'dataset.name': request.dataset!.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.updateDataset(request, options, callback);
   }
   getAnnotationSpec(
@@ -764,6 +795,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.getAnnotationSpec(request, options, callback);
   }
   getTableSpec(
@@ -838,6 +870,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.getTableSpec(request, options, callback);
   }
   updateTableSpec(
@@ -920,6 +953,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       'table_spec.name': request.tableSpec!.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.updateTableSpec(request, options, callback);
   }
   getColumnSpec(
@@ -994,6 +1028,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.getColumnSpec(request, options, callback);
   }
   updateColumnSpec(
@@ -1076,6 +1111,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       'column_spec.name': request.columnSpec!.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.updateColumnSpec(request, options, callback);
   }
   getModel(
@@ -1147,6 +1183,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.getModel(request, options, callback);
   }
   getModelEvaluation(
@@ -1227,6 +1264,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.getModelEvaluation(request, options, callback);
   }
 
@@ -1258,9 +1296,9 @@ export class AutoMlClient {
   /**
    * Deletes a dataset and all of its contents.
    * Returns empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes,
+   * {@link google.longrunning.Operation.response|response} field when it completes,
    * and `delete_details` in the
-   * [metadata][google.longrunning.Operation.metadata] field.
+   * {@link google.longrunning.Operation.metadata|metadata} field.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1318,6 +1356,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.deleteDataset(request, options, callback);
   }
   importData(
@@ -1351,10 +1390,10 @@ export class AutoMlClient {
    *
    * For Tables:
    * *   A
-   * [schema_inference_version][google.cloud.automl.v1beta1.InputConfig.params]
+   * {@link google.cloud.automl.v1beta1.InputConfig.params|schema_inference_version}
    *     parameter must be explicitly set.
    * Returns an empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes.
+   * {@link google.longrunning.Operation.response|response} field when it completes.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1416,6 +1455,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.importData(request, options, callback);
   }
   exportData(
@@ -1446,7 +1486,7 @@ export class AutoMlClient {
   /**
    * Exports dataset's data to the provided output location.
    * Returns an empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes.
+   * {@link google.longrunning.Operation.response|response} field when it completes.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1506,6 +1546,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.exportData(request, options, callback);
   }
   createModel(
@@ -1535,7 +1576,7 @@ export class AutoMlClient {
   ): void;
   /**
    * Creates a model.
-   * Returns a Model in the [response][google.longrunning.Operation.response]
+   * Returns a Model in the {@link google.longrunning.Operation.response|response}
    * field when it completes.
    * When you create a model, several model evaluations are created for it:
    * a global evaluation, and one evaluation for each annotation spec.
@@ -1598,6 +1639,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.createModel(request, options, callback);
   }
   deleteModel(
@@ -1628,9 +1670,9 @@ export class AutoMlClient {
   /**
    * Deletes a model.
    * Returns `google.protobuf.Empty` in the
-   * [response][google.longrunning.Operation.response] field when it completes,
+   * {@link google.longrunning.Operation.response|response} field when it completes,
    * and `delete_details` in the
-   * [metadata][google.longrunning.Operation.metadata] field.
+   * {@link google.longrunning.Operation.metadata|metadata} field.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1688,6 +1730,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.deleteModel(request, options, callback);
   }
   deployModel(
@@ -1720,14 +1763,14 @@ export class AutoMlClient {
    * same parameters has no effect. Deploying with different parametrs
    * (as e.g. changing
    *
-   * [node_number][google.cloud.automl.v1beta1.ImageObjectDetectionModelDeploymentMetadata.node_number])
+   * {@link google.cloud.automl.v1beta1.ImageObjectDetectionModelDeploymentMetadata.node_number|node_number})
    *  will reset the deployment state without pausing the model's availability.
    *
    * Only applicable for Text Classification, Image Object Detection , Tables, and Image Segmentation; all other domains manage
    * deployment automatically.
    *
    * Returns an empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes.
+   * {@link google.longrunning.Operation.response|response} field when it completes.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1789,6 +1832,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.deployModel(request, options, callback);
   }
   undeployModel(
@@ -1823,7 +1867,7 @@ export class AutoMlClient {
    * all other domains manage deployment automatically.
    *
    * Returns an empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes.
+   * {@link google.longrunning.Operation.response|response} field when it completes.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1881,6 +1925,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.undeployModel(request, options, callback);
   }
   exportModel(
@@ -1913,10 +1958,10 @@ export class AutoMlClient {
    * Storage location. A model is considered export-able if and only if it has
    * an export format defined for it in
    *
-   * [ModelExportOutputConfig][google.cloud.automl.v1beta1.ModelExportOutputConfig].
+   * {@link google.cloud.automl.v1beta1.ModelExportOutputConfig|ModelExportOutputConfig}.
    *
    * Returns an empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes.
+   * {@link google.longrunning.Operation.response|response} field when it completes.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -1976,6 +2021,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.exportModel(request, options, callback);
   }
   exportEvaluatedExamples(
@@ -2017,7 +2063,7 @@ export class AutoMlClient {
    * Currently only available for Tables.
    *
    * Returns an empty response in the
-   * [response][google.longrunning.Operation.response] field when it completes.
+   * {@link google.longrunning.Operation.response|response} field when it completes.
    *
    * @param {Object} request
    *   The request object that will be sent.
@@ -2078,6 +2124,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.exportEvaluatedExamples(
       request,
       options,
@@ -2124,8 +2171,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return
    *   Typically obtained via
-   *   [ListDatasetsResponse.next_page_token][google.cloud.automl.v1beta1.ListDatasetsResponse.next_page_token] of the previous
-   *   [AutoMl.ListDatasets][google.cloud.automl.v1beta1.AutoMl.ListDatasets] call.
+   *   {@link google.cloud.automl.v1beta1.ListDatasetsResponse.next_page_token|ListDatasetsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1beta1.AutoMl.ListDatasets|AutoMl.ListDatasets} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Promise} - The promise which resolves to an array.
@@ -2181,6 +2228,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.listDatasets(request, options, callback);
   }
 
@@ -2215,8 +2263,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return
    *   Typically obtained via
-   *   [ListDatasetsResponse.next_page_token][google.cloud.automl.v1beta1.ListDatasetsResponse.next_page_token] of the previous
-   *   [AutoMl.ListDatasets][google.cloud.automl.v1beta1.AutoMl.ListDatasets] call.
+   *   {@link google.cloud.automl.v1beta1.ListDatasetsResponse.next_page_token|ListDatasetsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1beta1.AutoMl.ListDatasets|AutoMl.ListDatasets} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Stream}
@@ -2236,6 +2284,7 @@ export class AutoMlClient {
       parent: request.parent || '',
     });
     const callSettings = new gax.CallSettings(options);
+    this.initialize();
     return this._descriptors.page.listDatasets.createStream(
       this._innerApiCalls.listDatasets as gax.GaxCall,
       request,
@@ -2278,8 +2327,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return.
    *   Typically obtained from the
-   *   [ListTableSpecsResponse.next_page_token][google.cloud.automl.v1beta1.ListTableSpecsResponse.next_page_token] field of the previous
-   *   [AutoMl.ListTableSpecs][google.cloud.automl.v1beta1.AutoMl.ListTableSpecs] call.
+   *   {@link google.cloud.automl.v1beta1.ListTableSpecsResponse.next_page_token|ListTableSpecsResponse.next_page_token} field of the previous
+   *   {@link google.cloud.automl.v1beta1.AutoMl.ListTableSpecs|AutoMl.ListTableSpecs} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Promise} - The promise which resolves to an array.
@@ -2335,6 +2384,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.listTableSpecs(request, options, callback);
   }
 
@@ -2365,8 +2415,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return.
    *   Typically obtained from the
-   *   [ListTableSpecsResponse.next_page_token][google.cloud.automl.v1beta1.ListTableSpecsResponse.next_page_token] field of the previous
-   *   [AutoMl.ListTableSpecs][google.cloud.automl.v1beta1.AutoMl.ListTableSpecs] call.
+   *   {@link google.cloud.automl.v1beta1.ListTableSpecsResponse.next_page_token|ListTableSpecsResponse.next_page_token} field of the previous
+   *   {@link google.cloud.automl.v1beta1.AutoMl.ListTableSpecs|AutoMl.ListTableSpecs} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Stream}
@@ -2386,6 +2436,7 @@ export class AutoMlClient {
       parent: request.parent || '',
     });
     const callSettings = new gax.CallSettings(options);
+    this.initialize();
     return this._descriptors.page.listTableSpecs.createStream(
       this._innerApiCalls.listTableSpecs as gax.GaxCall,
       request,
@@ -2428,8 +2479,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return.
    *   Typically obtained from the
-   *   [ListColumnSpecsResponse.next_page_token][google.cloud.automl.v1beta1.ListColumnSpecsResponse.next_page_token] field of the previous
-   *   [AutoMl.ListColumnSpecs][google.cloud.automl.v1beta1.AutoMl.ListColumnSpecs] call.
+   *   {@link google.cloud.automl.v1beta1.ListColumnSpecsResponse.next_page_token|ListColumnSpecsResponse.next_page_token} field of the previous
+   *   {@link google.cloud.automl.v1beta1.AutoMl.ListColumnSpecs|AutoMl.ListColumnSpecs} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Promise} - The promise which resolves to an array.
@@ -2485,6 +2536,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.listColumnSpecs(request, options, callback);
   }
 
@@ -2515,8 +2567,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return.
    *   Typically obtained from the
-   *   [ListColumnSpecsResponse.next_page_token][google.cloud.automl.v1beta1.ListColumnSpecsResponse.next_page_token] field of the previous
-   *   [AutoMl.ListColumnSpecs][google.cloud.automl.v1beta1.AutoMl.ListColumnSpecs] call.
+   *   {@link google.cloud.automl.v1beta1.ListColumnSpecsResponse.next_page_token|ListColumnSpecsResponse.next_page_token} field of the previous
+   *   {@link google.cloud.automl.v1beta1.AutoMl.ListColumnSpecs|AutoMl.ListColumnSpecs} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Stream}
@@ -2536,6 +2588,7 @@ export class AutoMlClient {
       parent: request.parent || '',
     });
     const callSettings = new gax.CallSettings(options);
+    this.initialize();
     return this._descriptors.page.listColumnSpecs.createStream(
       this._innerApiCalls.listColumnSpecs as gax.GaxCall,
       request,
@@ -2583,8 +2636,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return
    *   Typically obtained via
-   *   [ListModelsResponse.next_page_token][google.cloud.automl.v1beta1.ListModelsResponse.next_page_token] of the previous
-   *   [AutoMl.ListModels][google.cloud.automl.v1beta1.AutoMl.ListModels] call.
+   *   {@link google.cloud.automl.v1beta1.ListModelsResponse.next_page_token|ListModelsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1beta1.AutoMl.ListModels|AutoMl.ListModels} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Promise} - The promise which resolves to an array.
@@ -2640,6 +2693,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.listModels(request, options, callback);
   }
 
@@ -2675,8 +2729,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return
    *   Typically obtained via
-   *   [ListModelsResponse.next_page_token][google.cloud.automl.v1beta1.ListModelsResponse.next_page_token] of the previous
-   *   [AutoMl.ListModels][google.cloud.automl.v1beta1.AutoMl.ListModels] call.
+   *   {@link google.cloud.automl.v1beta1.ListModelsResponse.next_page_token|ListModelsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1beta1.AutoMl.ListModels|AutoMl.ListModels} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Stream}
@@ -2696,6 +2750,7 @@ export class AutoMlClient {
       parent: request.parent || '',
     });
     const callSettings = new gax.CallSettings(options);
+    this.initialize();
     return this._descriptors.page.listModels.createStream(
       this._innerApiCalls.listModels as gax.GaxCall,
       request,
@@ -2747,8 +2802,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return.
    *   Typically obtained via
-   *   [ListModelEvaluationsResponse.next_page_token][google.cloud.automl.v1beta1.ListModelEvaluationsResponse.next_page_token] of the previous
-   *   [AutoMl.ListModelEvaluations][google.cloud.automl.v1beta1.AutoMl.ListModelEvaluations] call.
+   *   {@link google.cloud.automl.v1beta1.ListModelEvaluationsResponse.next_page_token|ListModelEvaluationsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1beta1.AutoMl.ListModelEvaluations|AutoMl.ListModelEvaluations} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Promise} - The promise which resolves to an array.
@@ -2804,6 +2859,7 @@ export class AutoMlClient {
     ] = gax.routingHeader.fromParams({
       parent: request.parent || '',
     });
+    this.initialize();
     return this._innerApiCalls.listModelEvaluations(request, options, callback);
   }
 
@@ -2843,8 +2899,8 @@ export class AutoMlClient {
    * @param {string} request.pageToken
    *   A token identifying a page of results for the server to return.
    *   Typically obtained via
-   *   [ListModelEvaluationsResponse.next_page_token][google.cloud.automl.v1beta1.ListModelEvaluationsResponse.next_page_token] of the previous
-   *   [AutoMl.ListModelEvaluations][google.cloud.automl.v1beta1.AutoMl.ListModelEvaluations] call.
+   *   {@link google.cloud.automl.v1beta1.ListModelEvaluationsResponse.next_page_token|ListModelEvaluationsResponse.next_page_token} of the previous
+   *   {@link google.cloud.automl.v1beta1.AutoMl.ListModelEvaluations|AutoMl.ListModelEvaluations} call.
    * @param {object} [options]
    *   Call options. See {@link https://googleapis.dev/nodejs/google-gax/latest/interfaces/CallOptions.html|CallOptions} for more details.
    * @returns {Stream}
@@ -2864,6 +2920,7 @@ export class AutoMlClient {
       parent: request.parent || '',
     });
     const callSettings = new gax.CallSettings(options);
+    this.initialize();
     return this._descriptors.page.listModelEvaluations.createStream(
       this._innerApiCalls.listModelEvaluations as gax.GaxCall,
       request,
@@ -3322,8 +3379,9 @@ export class AutoMlClient {
    * The client will no longer be usable and all future behavior is undefined.
    */
   close(): Promise<void> {
+    this.initialize();
     if (!this._terminated) {
-      return this.autoMlStub.then(stub => {
+      return this.autoMlStub!.then(stub => {
         this._terminated = true;
         stub.close();
       });
diff --git a/packages/google-cloud-automl/src/v1beta1/prediction_service_client.ts b/packages/google-cloud-automl/src/v1beta1/prediction_service_client.ts
index ef590a33afe..500f2075513 100644
--- a/packages/google-cloud-automl/src/v1beta1/prediction_service_client.ts
+++ b/packages/google-cloud-automl/src/v1beta1/prediction_service_client.ts
@@ -45,9 +45,14 @@ export class PredictionServiceClient {
   private _innerApiCalls: {[name: string]: Function};
   private _pathTemplates: {[name: string]: gax.PathTemplate};
   private _terminated = false;
+  private _opts: ClientOptions;
+  private _gaxModule: typeof gax | typeof gax.fallback;
+  private _gaxGrpc: gax.GrpcClient | gax.fallback.GrpcClient;
+  private _protos: {};
+  private _defaults: {[method: string]: gax.CallSettings};
   auth: gax.GoogleAuth;
   operationsClient: gax.OperationsClient;
-  predictionServiceStub: Promise<{[name: string]: Function}>;
+  predictionServiceStub?: Promise<{[name: string]: Function}>;
 
   /**
    * Construct an instance of PredictionServiceClient.
@@ -71,8 +76,6 @@ export class PredictionServiceClient {
    *     app is running in an environment which supports
    *     {@link https://developers.google.com/identity/protocols/application-default-credentials Application Default Credentials},
    *     your project ID will be detected automatically.
-   * @param {function} [options.promise] - Custom promise module to use instead
-   *     of native Promises.
    * @param {string} [options.apiEndpoint] - The domain name of the
    *     API remote host.
    */
@@ -102,25 +105,28 @@ export class PredictionServiceClient {
     // If we are in browser, we are already using fallback because of the
     // "browser" field in package.json.
     // But if we were explicitly requested to use fallback, let's do it now.
-    const gaxModule = !isBrowser && opts.fallback ? gax.fallback : gax;
+    this._gaxModule = !isBrowser && opts.fallback ? gax.fallback : gax;
 
     // Create a `gaxGrpc` object, with any grpc-specific options
     // sent to the client.
     opts.scopes = (this.constructor as typeof PredictionServiceClient).scopes;
-    const gaxGrpc = new gaxModule.GrpcClient(opts);
+    this._gaxGrpc = new this._gaxModule.GrpcClient(opts);
+
+    // Save options to use in initialize() method.
+    this._opts = opts;
 
     // Save the auth object to the client, for use by other methods.
-    this.auth = gaxGrpc.auth as gax.GoogleAuth;
+    this.auth = this._gaxGrpc.auth as gax.GoogleAuth;
 
     // Determine the client header string.
-    const clientHeader = [`gax/${gaxModule.version}`, `gapic/${version}`];
+    const clientHeader = [`gax/${this._gaxModule.version}`, `gapic/${version}`];
     if (typeof process !== 'undefined' && 'versions' in process) {
       clientHeader.push(`gl-node/${process.versions.node}`);
     } else {
-      clientHeader.push(`gl-web/${gaxModule.version}`);
+      clientHeader.push(`gl-web/${this._gaxModule.version}`);
     }
     if (!opts.fallback) {
-      clientHeader.push(`grpc/${gaxGrpc.grpcVersion}`);
+      clientHeader.push(`grpc/${this._gaxGrpc.grpcVersion}`);
     }
     if (opts.libName && opts.libVersion) {
       clientHeader.push(`${opts.libName}/${opts.libVersion}`);
@@ -136,7 +142,7 @@ export class PredictionServiceClient {
       'protos',
       'protos.json'
     );
-    const protos = gaxGrpc.loadProto(
+    this._protos = this._gaxGrpc.loadProto(
       opts.fallback ? require('../../protos/protos.json') : nodejsProtoPath
     );
 
@@ -144,22 +150,22 @@ export class PredictionServiceClient {
     // identifiers to uniquely identify resources within the API.
     // Create useful helper objects for these.
     this._pathTemplates = {
-      annotationSpecPathTemplate: new gaxModule.PathTemplate(
+      annotationSpecPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}/annotationSpecs/{annotation_spec}'
       ),
-      columnSpecPathTemplate: new gaxModule.PathTemplate(
+      columnSpecPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}/tableSpecs/{table_spec}/columnSpecs/{column_spec}'
       ),
-      datasetPathTemplate: new gaxModule.PathTemplate(
+      datasetPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}'
       ),
-      modelPathTemplate: new gaxModule.PathTemplate(
+      modelPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/models/{model}'
       ),
-      modelEvaluationPathTemplate: new gaxModule.PathTemplate(
+      modelEvaluationPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/models/{model}/modelEvaluations/{model_evaluation}'
       ),
-      tableSpecPathTemplate: new gaxModule.PathTemplate(
+      tableSpecPathTemplate: new this._gaxModule.PathTemplate(
         'projects/{project}/locations/{location}/datasets/{dataset}/tableSpecs/{table_spec}'
       ),
     };
@@ -168,13 +174,15 @@ export class PredictionServiceClient {
     // an Operation object that allows for tracking of the operation,
     // rather than holding a request open.
     const protoFilesRoot = opts.fallback
-      ? gaxModule.protobuf.Root.fromJSON(require('../../protos/protos.json'))
-      : gaxModule.protobuf.loadSync(nodejsProtoPath);
+      ? this._gaxModule.protobuf.Root.fromJSON(
+          require('../../protos/protos.json')
+        )
+      : this._gaxModule.protobuf.loadSync(nodejsProtoPath);
 
-    this.operationsClient = gaxModule
+    this.operationsClient = this._gaxModule
       .lro({
         auth: this.auth,
-        grpc: 'grpc' in gaxGrpc ? gaxGrpc.grpc : undefined,
+        grpc: 'grpc' in this._gaxGrpc ? this._gaxGrpc.grpc : undefined,
       })
       .operationsClient(opts);
     const batchPredictResponse = protoFilesRoot.lookup(
@@ -185,7 +193,7 @@ export class PredictionServiceClient {
     ) as gax.protobuf.Type;
 
     this._descriptors.longrunning = {
-      batchPredict: new gaxModule.LongrunningDescriptor(
+      batchPredict: new this._gaxModule.LongrunningDescriptor(
         this.operationsClient,
         batchPredictResponse.decode.bind(batchPredictResponse),
         batchPredictMetadata.decode.bind(batchPredictMetadata)
@@ -193,7 +201,7 @@ export class PredictionServiceClient {
     };
 
     // Put together the default options sent with requests.
-    const defaults = gaxGrpc.constructSettings(
+    this._defaults = this._gaxGrpc.constructSettings(
       'google.cloud.automl.v1beta1.PredictionService',
       gapicConfig as gax.ClientConfig,
       opts.clientConfig || {},
@@ -204,17 +212,35 @@ export class PredictionServiceClient {
     // of calling the API is handled in `google-gax`, with this code
     // merely providing the destination and request information.
     this._innerApiCalls = {};
+  }
+
+  /**
+   * Initialize the client.
+   * Performs asynchronous operations (such as authentication) and prepares the client.
+   * This function will be called automatically when any class method is called for the
+   * first time, but if you need to initialize it before calling an actual method,
+   * feel free to call initialize() directly.
+   *
+   * You can await on this method if you want to make sure the client is initialized.
+   *
+   * @returns {Promise} A promise that resolves to an authenticated service stub.
+   */
+  initialize() {
+    // If the client stub promise is already initialized, return immediately.
+    if (this.predictionServiceStub) {
+      return this.predictionServiceStub;
+    }
 
     // Put together the "service stub" for
     // google.cloud.automl.v1beta1.PredictionService.
-    this.predictionServiceStub = gaxGrpc.createStub(
-      opts.fallback
-        ? (protos as protobuf.Root).lookupService(
+    this.predictionServiceStub = this._gaxGrpc.createStub(
+      this._opts.fallback
+        ? (this._protos as protobuf.Root).lookupService(
             'google.cloud.automl.v1beta1.PredictionService'
           )
         : // tslint:disable-next-line no-any
-          (protos as any).google.cloud.automl.v1beta1.PredictionService,
-      opts
+          (this._protos as any).google.cloud.automl.v1beta1.PredictionService,
+      this._opts
     ) as Promise<{[method: string]: Function}>;
 
     // Iterate over each of the methods that the service provides
@@ -234,9 +260,9 @@ export class PredictionServiceClient {
         }
       );
 
-      const apiCall = gaxModule.createApiCall(
+      const apiCall = this._gaxModule.createApiCall(
         innerCallPromise,
-        defaults[methodName],
+        this._defaults[methodName],
         this._descriptors.page[methodName] ||
           this._descriptors.stream[methodName] ||
           this._descriptors.longrunning[methodName]
@@ -250,6 +276,8 @@ export class PredictionServiceClient {
         return apiCall(argument, callOptions, callback);
       };
     }
+
+    return this.predictionServiceStub;
   }
 
   /**
@@ -338,7 +366,7 @@ export class PredictionServiceClient {
    * * Tables - Row, with column values matching the columns of the model,
    *            up to 5MB. Not available for FORECASTING
    *
-   * [prediction_type][google.cloud.automl.v1beta1.TablesModelMetadata.prediction_type].
+   * {@link google.cloud.automl.v1beta1.TablesModelMetadata.prediction_type|prediction_type}.
    * * Text Sentiment - TextSnippet, content up 500 characters, UTF-8
    *                     encoded.
    *
@@ -413,6 +441,7 @@ export class PredictionServiceClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.predict(request, options, callback);
   }
 
@@ -442,12 +471,12 @@ export class PredictionServiceClient {
     >
   ): void;
   /**
-   * Perform a batch prediction. Unlike the online [Predict][google.cloud.automl.v1beta1.PredictionService.Predict], batch
+   * Perform a batch prediction. Unlike the online {@link google.cloud.automl.v1beta1.PredictionService.Predict|Predict}, batch
    * prediction result won't be immediately available in the response. Instead,
    * a long running operation object is returned. User can poll the operation
-   * result via [GetOperation][google.longrunning.Operations.GetOperation]
-   * method. Once the operation is done, [BatchPredictResult][google.cloud.automl.v1beta1.BatchPredictResult] is returned in
-   * the [response][google.longrunning.Operation.response] field.
+   * result via {@link google.longrunning.Operations.GetOperation|GetOperation}
+   * method. Once the operation is done, {@link google.cloud.automl.v1beta1.BatchPredictResult|BatchPredictResult} is returned in
+   * the {@link google.longrunning.Operation.response|response} field.
    * Available for following ML problems:
    * * Image Classification
    * * Image Object Detection
@@ -587,6 +616,7 @@ export class PredictionServiceClient {
     ] = gax.routingHeader.fromParams({
       name: request.name || '',
     });
+    this.initialize();
     return this._innerApiCalls.batchPredict(request, options, callback);
   }
   // --------------------
@@ -1004,8 +1034,9 @@ export class PredictionServiceClient {
    * The client will no longer be usable and all future behavior is undefined.
    */
   close(): Promise<void> {
+    this.initialize();
     if (!this._terminated) {
-      return this.predictionServiceStub.then(stub => {
+      return this.predictionServiceStub!.then(stub => {
         this._terminated = true;
         stub.close();
       });
diff --git a/packages/google-cloud-automl/synth.metadata b/packages/google-cloud-automl/synth.metadata
index 05e0d034c5a..8262e149b52 100644
--- a/packages/google-cloud-automl/synth.metadata
+++ b/packages/google-cloud-automl/synth.metadata
@@ -1,5 +1,5 @@
 {
-  "updateTime": "2020-03-05T22:40:22.969554Z",
+  "updateTime": "2020-03-06T12:13:29.324535Z",
   "sources": [
     {
       "git": {
diff --git a/packages/google-cloud-automl/test/gapic-auto_ml-v1.ts b/packages/google-cloud-automl/test/gapic-auto_ml-v1.ts
index d4cdcb59105..a583b0bc13f 100644
--- a/packages/google-cloud-automl/test/gapic-auto_ml-v1.ts
+++ b/packages/google-cloud-automl/test/gapic-auto_ml-v1.ts
@@ -102,12 +102,30 @@ describe('v1.AutoMlClient', () => {
     });
     assert(client);
   });
+  it('has initialize method and supports deferred initialization', async () => {
+    const client = new automlModule.v1.AutoMlClient({
+      credentials: {client_email: 'bogus', private_key: 'bogus'},
+      projectId: 'bogus',
+    });
+    assert.strictEqual(client.autoMlStub, undefined);
+    await client.initialize();
+    assert(client.autoMlStub);
+  });
+  it('has close method', () => {
+    const client = new automlModule.v1.AutoMlClient({
+      credentials: {client_email: 'bogus', private_key: 'bogus'},
+      projectId: 'bogus',
+    });
+    client.close();
+  });
   describe('getDataset', () => {
     it('invokes getDataset without error', done => {
       const client = new automlModule.v1.AutoMlClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IGetDatasetRequest = {};
       request.name = '';
@@ -131,6 +149,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IGetDatasetRequest = {};
       request.name = '';
@@ -156,6 +176,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IUpdateDatasetRequest = {};
       request.dataset = {};
@@ -180,6 +202,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IUpdateDatasetRequest = {};
       request.dataset = {};
@@ -206,6 +230,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IGetAnnotationSpecRequest = {};
       request.name = '';
@@ -229,6 +255,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IGetAnnotationSpecRequest = {};
       request.name = '';
@@ -254,6 +282,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IGetModelRequest = {};
       request.name = '';
@@ -277,6 +307,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IGetModelRequest = {};
       request.name = '';
@@ -302,6 +334,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IUpdateModelRequest = {};
       request.model = {};
@@ -326,6 +360,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IUpdateModelRequest = {};
       request.model = {};
@@ -352,6 +388,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IGetModelEvaluationRequest = {};
       request.name = '';
@@ -375,6 +413,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IGetModelEvaluationRequest = {};
       request.name = '';
@@ -400,6 +440,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.ICreateDatasetRequest = {};
       request.parent = '';
@@ -430,6 +472,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.ICreateDatasetRequest = {};
       request.parent = '';
@@ -463,6 +507,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IDeleteDatasetRequest = {};
       request.name = '';
@@ -493,6 +539,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IDeleteDatasetRequest = {};
       request.name = '';
@@ -526,6 +574,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IImportDataRequest = {};
       request.name = '';
@@ -556,6 +606,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IImportDataRequest = {};
       request.name = '';
@@ -589,6 +641,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IExportDataRequest = {};
       request.name = '';
@@ -619,6 +673,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IExportDataRequest = {};
       request.name = '';
@@ -652,6 +708,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.ICreateModelRequest = {};
       request.parent = '';
@@ -682,6 +740,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.ICreateModelRequest = {};
       request.parent = '';
@@ -715,6 +775,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IDeleteModelRequest = {};
       request.name = '';
@@ -745,6 +807,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IDeleteModelRequest = {};
       request.name = '';
@@ -778,6 +842,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IDeployModelRequest = {};
       request.name = '';
@@ -808,6 +874,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IDeployModelRequest = {};
       request.name = '';
@@ -841,6 +909,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IUndeployModelRequest = {};
       request.name = '';
@@ -871,6 +941,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IUndeployModelRequest = {};
       request.name = '';
@@ -904,6 +976,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IExportModelRequest = {};
       request.name = '';
@@ -934,6 +1008,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IExportModelRequest = {};
       request.name = '';
@@ -967,6 +1043,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IListDatasetsRequest = {};
       request.parent = '';
@@ -994,6 +1072,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IListDatasetsRequest = {};
       request.parent = '';
@@ -1026,6 +1106,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IListModelsRequest = {};
       request.parent = '';
@@ -1053,6 +1135,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IListModelsRequest = {};
       request.parent = '';
@@ -1085,6 +1169,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IListModelEvaluationsRequest = {};
       request.parent = '';
@@ -1112,6 +1198,8 @@ describe('v1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IListModelEvaluationsRequest = {};
       request.parent = '';
diff --git a/packages/google-cloud-automl/test/gapic-auto_ml-v1beta1.ts b/packages/google-cloud-automl/test/gapic-auto_ml-v1beta1.ts
index cd3bc2f0c64..688706cf54e 100644
--- a/packages/google-cloud-automl/test/gapic-auto_ml-v1beta1.ts
+++ b/packages/google-cloud-automl/test/gapic-auto_ml-v1beta1.ts
@@ -102,12 +102,30 @@ describe('v1beta1.AutoMlClient', () => {
     });
     assert(client);
   });
+  it('has initialize method and supports deferred initialization', async () => {
+    const client = new automlModule.v1beta1.AutoMlClient({
+      credentials: {client_email: 'bogus', private_key: 'bogus'},
+      projectId: 'bogus',
+    });
+    assert.strictEqual(client.autoMlStub, undefined);
+    await client.initialize();
+    assert(client.autoMlStub);
+  });
+  it('has close method', () => {
+    const client = new automlModule.v1beta1.AutoMlClient({
+      credentials: {client_email: 'bogus', private_key: 'bogus'},
+      projectId: 'bogus',
+    });
+    client.close();
+  });
   describe('createDataset', () => {
     it('invokes createDataset without error', done => {
       const client = new automlModule.v1beta1.AutoMlClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.ICreateDatasetRequest = {};
       request.parent = '';
@@ -131,6 +149,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.ICreateDatasetRequest = {};
       request.parent = '';
@@ -156,6 +176,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetDatasetRequest = {};
       request.name = '';
@@ -179,6 +201,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetDatasetRequest = {};
       request.name = '';
@@ -204,6 +228,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IUpdateDatasetRequest = {};
       request.dataset = {};
@@ -228,6 +254,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IUpdateDatasetRequest = {};
       request.dataset = {};
@@ -254,6 +282,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetAnnotationSpecRequest = {};
       request.name = '';
@@ -277,6 +307,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetAnnotationSpecRequest = {};
       request.name = '';
@@ -302,6 +334,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetTableSpecRequest = {};
       request.name = '';
@@ -325,6 +359,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetTableSpecRequest = {};
       request.name = '';
@@ -350,6 +386,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IUpdateTableSpecRequest = {};
       request.tableSpec = {};
@@ -374,6 +412,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IUpdateTableSpecRequest = {};
       request.tableSpec = {};
@@ -400,6 +440,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetColumnSpecRequest = {};
       request.name = '';
@@ -423,6 +465,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetColumnSpecRequest = {};
       request.name = '';
@@ -448,6 +492,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IUpdateColumnSpecRequest = {};
       request.columnSpec = {};
@@ -472,6 +518,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IUpdateColumnSpecRequest = {};
       request.columnSpec = {};
@@ -498,6 +546,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetModelRequest = {};
       request.name = '';
@@ -521,6 +571,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetModelRequest = {};
       request.name = '';
@@ -546,6 +598,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetModelEvaluationRequest = {};
       request.name = '';
@@ -569,6 +623,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IGetModelEvaluationRequest = {};
       request.name = '';
@@ -594,6 +650,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IDeleteDatasetRequest = {};
       request.name = '';
@@ -624,6 +682,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IDeleteDatasetRequest = {};
       request.name = '';
@@ -657,6 +717,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IImportDataRequest = {};
       request.name = '';
@@ -687,6 +749,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IImportDataRequest = {};
       request.name = '';
@@ -720,6 +784,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IExportDataRequest = {};
       request.name = '';
@@ -750,6 +816,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IExportDataRequest = {};
       request.name = '';
@@ -783,6 +851,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.ICreateModelRequest = {};
       request.parent = '';
@@ -813,6 +883,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.ICreateModelRequest = {};
       request.parent = '';
@@ -846,6 +918,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IDeleteModelRequest = {};
       request.name = '';
@@ -876,6 +950,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IDeleteModelRequest = {};
       request.name = '';
@@ -909,6 +985,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IDeployModelRequest = {};
       request.name = '';
@@ -939,6 +1017,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IDeployModelRequest = {};
       request.name = '';
@@ -972,6 +1052,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IUndeployModelRequest = {};
       request.name = '';
@@ -1002,6 +1084,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IUndeployModelRequest = {};
       request.name = '';
@@ -1035,6 +1119,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IExportModelRequest = {};
       request.name = '';
@@ -1065,6 +1151,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IExportModelRequest = {};
       request.name = '';
@@ -1098,6 +1186,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IExportEvaluatedExamplesRequest = {};
       request.name = '';
@@ -1128,6 +1218,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IExportEvaluatedExamplesRequest = {};
       request.name = '';
@@ -1161,6 +1253,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IListDatasetsRequest = {};
       request.parent = '';
@@ -1188,6 +1282,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IListDatasetsRequest = {};
       request.parent = '';
@@ -1220,6 +1316,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IListTableSpecsRequest = {};
       request.parent = '';
@@ -1247,6 +1345,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IListTableSpecsRequest = {};
       request.parent = '';
@@ -1279,6 +1379,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IListColumnSpecsRequest = {};
       request.parent = '';
@@ -1306,6 +1408,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IListColumnSpecsRequest = {};
       request.parent = '';
@@ -1338,6 +1442,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IListModelsRequest = {};
       request.parent = '';
@@ -1365,6 +1471,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IListModelsRequest = {};
       request.parent = '';
@@ -1397,6 +1505,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IListModelEvaluationsRequest = {};
       request.parent = '';
@@ -1424,6 +1534,8 @@ describe('v1beta1.AutoMlClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IListModelEvaluationsRequest = {};
       request.parent = '';
diff --git a/packages/google-cloud-automl/test/gapic-prediction_service-v1.ts b/packages/google-cloud-automl/test/gapic-prediction_service-v1.ts
index 0db8ea518f7..ec477267a55 100644
--- a/packages/google-cloud-automl/test/gapic-prediction_service-v1.ts
+++ b/packages/google-cloud-automl/test/gapic-prediction_service-v1.ts
@@ -104,12 +104,30 @@ describe('v1.PredictionServiceClient', () => {
     });
     assert(client);
   });
+  it('has initialize method and supports deferred initialization', async () => {
+    const client = new predictionserviceModule.v1.PredictionServiceClient({
+      credentials: {client_email: 'bogus', private_key: 'bogus'},
+      projectId: 'bogus',
+    });
+    assert.strictEqual(client.predictionServiceStub, undefined);
+    await client.initialize();
+    assert(client.predictionServiceStub);
+  });
+  it('has close method', () => {
+    const client = new predictionserviceModule.v1.PredictionServiceClient({
+      credentials: {client_email: 'bogus', private_key: 'bogus'},
+      projectId: 'bogus',
+    });
+    client.close();
+  });
   describe('predict', () => {
     it('invokes predict without error', done => {
       const client = new predictionserviceModule.v1.PredictionServiceClient({
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IPredictRequest = {};
       request.name = '';
@@ -133,6 +151,8 @@ describe('v1.PredictionServiceClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IPredictRequest = {};
       request.name = '';
@@ -158,6 +178,8 @@ describe('v1.PredictionServiceClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IBatchPredictRequest = {};
       request.name = '';
@@ -188,6 +210,8 @@ describe('v1.PredictionServiceClient', () => {
         credentials: {client_email: 'bogus', private_key: 'bogus'},
         projectId: 'bogus',
       });
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1.IBatchPredictRequest = {};
       request.name = '';
diff --git a/packages/google-cloud-automl/test/gapic-prediction_service-v1beta1.ts b/packages/google-cloud-automl/test/gapic-prediction_service-v1beta1.ts
index 7668630686d..bdc58f12fa4 100644
--- a/packages/google-cloud-automl/test/gapic-prediction_service-v1beta1.ts
+++ b/packages/google-cloud-automl/test/gapic-prediction_service-v1beta1.ts
@@ -104,6 +104,22 @@ describe('v1beta1.PredictionServiceClient', () => {
     });
     assert(client);
   });
+  it('has initialize method and supports deferred initialization', async () => {
+    const client = new predictionserviceModule.v1beta1.PredictionServiceClient({
+      credentials: {client_email: 'bogus', private_key: 'bogus'},
+      projectId: 'bogus',
+    });
+    assert.strictEqual(client.predictionServiceStub, undefined);
+    await client.initialize();
+    assert(client.predictionServiceStub);
+  });
+  it('has close method', () => {
+    const client = new predictionserviceModule.v1beta1.PredictionServiceClient({
+      credentials: {client_email: 'bogus', private_key: 'bogus'},
+      projectId: 'bogus',
+    });
+    client.close();
+  });
   describe('predict', () => {
     it('invokes predict without error', done => {
       const client = new predictionserviceModule.v1beta1.PredictionServiceClient(
@@ -112,6 +128,8 @@ describe('v1beta1.PredictionServiceClient', () => {
           projectId: 'bogus',
         }
       );
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IPredictRequest = {};
       request.name = '';
@@ -137,6 +155,8 @@ describe('v1beta1.PredictionServiceClient', () => {
           projectId: 'bogus',
         }
       );
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IPredictRequest = {};
       request.name = '';
@@ -164,6 +184,8 @@ describe('v1beta1.PredictionServiceClient', () => {
           projectId: 'bogus',
         }
       );
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IBatchPredictRequest = {};
       request.name = '';
@@ -196,6 +218,8 @@ describe('v1beta1.PredictionServiceClient', () => {
           projectId: 'bogus',
         }
       );
+      // Initialize client before mocking
+      client.initialize();
       // Mock request
       const request: protosTypes.google.cloud.automl.v1beta1.IBatchPredictRequest = {};
       request.name = '';