@Override
 public void addToPlaylist(List<MRL> mediaLocators) {
   if (engine instanceof PlaylistSupport) {
     ((PlaylistSupport) engine).addToPlaylist(mediaLocators);
   }
 }
 @Override
 public void addToPlaylist(String... mediaURLs) {
   if (engine instanceof PlaylistSupport) {
     ((PlaylistSupport) engine).addToPlaylist(mediaURLs);
   }
 }