code: public void setBarEffectEnabled(final boolean ENABLED) {
          if (null == barEffectEnabled) {
              _barEffectEnabled = ENABLED;
              fireUpdateEvent(VISIBILITY_EVENT);
          } else {
              barEffectEnabled.set(ENABLED);
          }
      }
docs: Defines if the the highlight effect on the gauges like the
  LinearSkin bar will be drawn. If you would like to have a
  more flat style you should set this to false.
  
  @param ENABLED