@java.lang.Override
    @java.lang.SuppressWarnings("unchecked")
    public void invoke(Req request, io.grpc.stub.StreamObserver<Resp> responseObserver) {
      switch (methodId) {
        case METHODID_LIST_VOICES:
          serviceImpl.listVoices(
              (com.google.cloud.texttospeech.v1beta1.ListVoicesRequest) request,
              (io.grpc.stub.StreamObserver<
                      com.google.cloud.texttospeech.v1beta1.ListVoicesResponse>)
                  responseObserver);
          break;
        case METHODID_SYNTHESIZE_SPEECH:
          serviceImpl.synthesizeSpeech(
              (com.google.cloud.texttospeech.v1beta1.SynthesizeSpeechRequest) request,
              (io.grpc.stub.StreamObserver<
                      com.google.cloud.texttospeech.v1beta1.SynthesizeSpeechResponse>)
                  responseObserver);
          break;
        default:
          throw new AssertionError();
      }
    }
<pre>
Synthesizes speech synchronously: receive results after all text input
has been processed.
</pre>
java-texttospeech/grpc-google-cloud-texttospeech-v1beta1/src/main/java/com/google/cloud/texttospeech/v1beta1/TextToSpeechGrpc.java