getVoices method Null safety

List<SpeechSynthesisVoice> getVoices ()

Implementation

List<SpeechSynthesisVoice> getVoices() {
  List<SpeechSynthesisVoice> voices = _getVoices();
  if (voices.length > 0) applyExtension('SpeechSynthesisVoice', voices[0]);
  return voices;
}