@Override
  public <RequestT, ResponseT> UnaryCallable<RequestT, ResponseT> createUnaryCallable(
      GrpcCallSettings<RequestT, ResponseT> grpcCallSettings,
      UnaryCallSettings<RequestT, ResponseT> callSettings,
      ClientContext clientContext) {
    return GrpcCallableFactory.createUnaryCallable(grpcCallSettings, callSettings, clientContext);
  }
gRPC callable factory implementation for the TextToSpeechLongAudioSynthesize service API.

<p>This class is for advanced usage.
java-texttospeech/google-cloud-texttospeech/src/main/java/com/google/cloud/texttospeech/v1/stub/GrpcTextToSpeechLongAudioSynthesizeCallableFactory.java