anchor.diff:          }
         }
         if (_playlist!.hasNext()) {
  -        final curr = _current.value;
  +        final curr = _current.valueOrNull;
           if (curr != null) {
             _playlistAudioFinished.add(Playing(
               audio: curr.audio,
  
positive.code:   ///
    Future<void> seekBy(Duration by) async {
      // only if playing a song
      final playing = current.value;
      if (playing != null) {
        final totalDuration = playing.audio.duration;
  
  
negative.code:   void onAudioReplacedAt(int index, bool keepPlayingPositionIfCurrent) {
      assetsAudioPlayer._updatePlaylistIndexes();
      if (assetsAudioPlayer._playlist!.playlistIndex == index) {
        final currentPosition = assetsAudioPlayer.currentPosition.valueOrNull;
        final isPlaying = assetsAudioPlayer.isPlaying.valueOrNull ?? false;
        //print('onAudioReplacedAt/ currentPosition : $currentPosition');
        if (keepPlayingPositionIfCurrent && currentPosition != null) {
  