anchor.diff:    ///       assets:
     ///         - assets/audios/
     ///
  -  void open(Playable playable, {
  +  void open(
  +    Playable playable, {
       bool autoStart = _DEFAULT_AUTO_START,
       double volume,
       bool respectSilentMode = _DEFAULT_RESPECT_SILENT_MODE,
  
positive.code:         volume: volume,
          seek: seek,
          respectSilentMode: respectSilentMode,
          autoStart: true
      );
    }
  
    ReadingPlaylist get playlist {
  
negative.code:           autoStart: autoStart,
            volume: volume,
            respectSilentMode: respectSilentMode,
            seek: seek);
      } else if (playable is Audio) {
        _openPlaylist(Playlist(audios: [playable]),
            autoStart: autoStart,
            volume: volume,
            respectSilentMode: respectSilentMode,
            seek: seek);
      } else {
        //do nothing
        //throw exception ?
  