code: protected synchronized void fireOutputChangeEvent(OUTPUT_EVENT event) {
          OutputChangeEvent oce = new OutputChangeEvent(this, event);
  
          for (OutputChangeListener pcl : outputListeners) {
              pcl.outputChanged(oce);
          }
      }
docs: Sends the appropriate {@link org.bff.javampd.playlist.PlaylistChangeEvent} to all registered
  {@link org.bff.javampd.playlist.PlaylistChangeListener}.
  
  @param event the event id to send