anchor.diff:  
     /// returns the looping state : true -> looping, false -> not looping
     bool get loop => _loop.value;
  -  bool get shuffle => _loop.value;
  +  bool get shuffle => _shuffle.value;
   
     bool _respectSilentMode = _DEFAULT_RESPECT_SILENT_MODE;
   
  
positive.code:     }
    }
  
    Future<bool> next({bool stopIfLast = false, bool shuffle = false}) {
      return _next(
        stopIfLast: stopIfLast,
        requestByUser: true,
  
negative.code:     return playlistIndex;
    }
  
    List<int> playedAudios = [];
  
    int shuffle() {
      playlistIndex = _shuffleNumbers();
      playedAudios.add(playlistIndex);
      return playlistIndex;
    }
  
    int _shuffleNumbers() {
      Random random = Random();
      int index = random.nextInt(playlist.audios.length);
      if (playedAudios.contains(index)) {
        index = _shuffleNumbers();
      }
      return index;
  