anchor.diff:      getShadowRoot("media-bar").applyAuthorStyles = true;
   
       toggleSoundButton = $["toggleSound"];
  +    toggleSoundImage = toggleSoundButton.children.first;
       volumeSlider = new RangeSlider($["volumeSlider"]);
       stream = $["audioElement"];
   
  
positive.code:     volumeSlider.value = vol;
  
      // Initially play the stream
      toggleSound(null);
  
      // Set the volume slider listeners.
      volumeSlider.$elmt.onChange.listen((CustomEvent e) {
  
negative.code:   RangeSlider volumeSlider;
    bool isPlaying;
    AudioElement stream;
    ImageElement toggleSoundImage;
  
    MediaBar.created()
      : super.created() {
  