setRemoteAudioVolume method Null safety
Set the playback volume of the specified remote user
Parameters:
userId Remote user ID
volume Volume. Value range: 0–100
Implementation
Future<void> setRemoteAudioVolume(
    String userId, // Remote user ID
    int volume // Volume. Value range: 0–100
    ) {
  return _channel.invokeMethod('setRemoteAudioVolume', {
    "userId": userId,
    "volume": volume,
  });
}