multiSpeakerTTS method
Configure for multi-speaker TTS
Implementation
GoogleLLMBuilder multiSpeakerTTS({
  Map<String, String>? defaultSpeakerVoices,
  String? model,
}) {
  if (model != null) {
    ttsModel(model);
  }
  if (defaultSpeakerVoices != null) {
    _baseBuilder.extension('defaultSpeakerVoices', defaultSpeakerVoices);
  }
  return this;
}