code: private void addLabelHoverHandler(Label label) {
  
          removeLabelHoverHandler();
          LabelHoverHandler hoverHandler = new LabelHoverHandler();
          m_labelOutRegistration = label.addMouseOutHandler(hoverHandler);
          m_labelOverRegistration = label.addMouseOverHandler(hoverHandler);
      }
docs: Adds the label hover mouse handler.<p>
  
  @param label the label widget