@Override
  public OperationCallable<
          TransferProto.RunTransferJobRequest, Empty, TransferTypes.TransferOperation>
      runTransferJobOperationCallable() {
    return runTransferJobOperationCallable;
  }
Constructs an instance of HttpJsonStorageTransferServiceStub, using the given settings. This is
protected so that it is easy to make a subclass, but otherwise, the static factory methods
should be preferred.
java-storage-transfer/google-cloud-storage-transfer/src/main/java/com/google/storagetransfer/v1/proto/stub/HttpJsonStorageTransferServiceStub.java