disposeEngine method

Implementation

@override
Future<void> disposeEngine() async {
  await cancelScheduledNotes();
  await panic();
  for (final synthId in _synths.keys.toList()) {
    await disposeSynth(synthId);
  }
  final masterGain = _masterGain;
  if (masterGain != null) {
    masterGain.callMethod<JSAny?>('dispose'.toJS);
    _masterGain = null;
  }
}