code: public void highlightElement() {
  
          CmsPositionBean position = CmsPositionBean.getBoundingClientRect(getElement());
          if (m_highlighting == null) {
              m_highlighting = new CmsHighlightingBorder(
                  position,
                  isNew() || (CmsContainerpageController.get().getData().isModelPage() && isCreateNew())
                  ? CmsHighlightingBorder.BorderColor.blue
                  : CmsHighlightingBorder.BorderColor.red);
              RootPanel.get().add(m_highlighting);
          } else {
              m_highlighting.setPosition(position);
          }
      }
docs: Puts a highlighting border around the element.<p>