@Override
  public void shutdownNow() {
    stub.shutdownNow();
  }
Run asynchronous image detection and annotation for a list of generic files, such as PDF files,
which may contain multiple pages and multiple images per page. Progress and results can be
retrieved through the `google.longrunning.Operations` interface. `Operation.metadata` contains
`OperationMetadata` (metadata). `Operation.response` contains `AsyncBatchAnnotateFilesResponse`
(results).

<p>Sample code:

<pre>{@code
// This snippet has been automatically generated and should be regarded as a code template only.
// It will require modifications to work:
// - It may require correct/in-range values for request initialization.
// - It may require specifying regional endpoints when creating the service client as shown in
// https://cloud.google.com/java/docs/setup#configure_endpoints_for_the_client_library
try (ImageAnnotatorClient imageAnnotatorClient = ImageAnnotatorClient.create()) {
  AsyncBatchAnnotateFilesRequest request =
      AsyncBatchAnnotateFilesRequest.newBuilder()
          .addAllRequests(new ArrayList<AsyncAnnotateFileRequest>())
          .build();
  ApiFuture<Operation> future =
      imageAnnotatorClient.asyncBatchAnnotateFilesCallable().futureCall(request);
  // Do something.
  Operation response = future.get();
}
}</pre>
java-vision/google-cloud-vision/src/main/java/com/google/cloud/vision/v1p3beta1/ImageAnnotatorClient.java