setMusicSpeedRate method
Adjust the speed of background music
Parameters:
id Music track ID
speedRate Speed. Default value: 1.0f. Value range: floating point between [0.5,2];
Platform not supported:
- web
 
Implementation
Future<void> setMusicSpeedRate(int id, double speedRate) {
  return _channel.invokeMethod(
      'setMusicSpeedRate', {"id": id, "speedRate": speedRate.toString()});
}