code: @Override
      protected void onLoad() {
  
          mainAbsolutePanel.setSize(
                  String.valueOf(yuiSliderGwtWidget.getOffsetWidth()),
                  String.valueOf(yuiSliderGwtWidget.getOffsetHeight())
          );
  
          setupMarkerLabels();
  
      }
docs: override onLoad to know when absolutePanel's size can be set