anchor.diff:    SoundEffect sound;
     bool playing = false;
     bool loop = false;
  -  double time = 0.0;
     double volume = 1.0;
     double pitch = 1.0;
     double pan = 0.0;
  
positive.code: 
        // Prepare sound, then play it
        _prepare(playingSound).then((_) {
          playingSound._player.ptr.seekTo((startTime * 1000.0).toInt());
          playingSound._player.ptr.start();
        });
  
  
negative.code:       double volume = 1.0,
        double pitch = 1.0,
        double pan = 0.0,
        SoundCompleteCallback callback = null]) {
  
      // Create new PlayingSound object
  