code: protected void setElementVisible(Widget widget, boolean visible) {
  
          if (visible) {
              widget.getElement().getStyle().clearDisplay();
          } else {
              widget.getElement().getStyle().setDisplay(Display.NONE);
          }
  
      }
docs: Shows or hides the element for a widget.<p>
  
  @param widget the widget to show or hide
  @param visible true if the widget should be shown