public UnaryCallable<SynthesizeSpeechRequest, SynthesizeSpeechResponse>
      synthesizeSpeechCallable() {
    throw new UnsupportedOperationException("Not implemented: synthesizeSpeechCallable()");
  }
Base stub class for the TextToSpeech service API.

<p>This class is for advanced usage and reflects the underlying API directly.
java-texttospeech/google-cloud-texttospeech/src/main/java/com/google/cloud/texttospeech/v1/stub/TextToSpeechStub.java