public final UnaryCallable<TransferProto.RunTransferJobRequest, Operation>
      runTransferJobCallable() {
    return stub.runTransferJobCallable();
  }
Starts a new operation for the specified transfer job. A `TransferJob` has a maximum of one
active `TransferOperation`. If this method is called while a `TransferOperation` is active, an
error is returned.

<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 (StorageTransferServiceClient storageTransferServiceClient =
    StorageTransferServiceClient.create()) {
  TransferProto.RunTransferJobRequest request =
      TransferProto.RunTransferJobRequest.newBuilder()
          .setJobName("jobName-1438096408")
          .setProjectId("projectId-894832108")
          .build();
  ApiFuture<Operation> future =
      storageTransferServiceClient.runTransferJobCallable().futureCall(request);
  // Do something.
  future.get();
}
}</pre>
java-storage-transfer/google-cloud-storage-transfer/src/main/java/com/google/storagetransfer/v1/proto/StorageTransferServiceClient.java