code: public void addContentAndShow(List<Label> content, int left, int top, boolean showCloseButton) {
  
  		// Add a closeButton when showCloseButton is true.
  		if (showCloseButton) {
  			Label closeButtonLabel = new Label(" X ");
  			closeButtonLabel.addStyleName(ToolTipResource.INSTANCE.css().toolTipCloseButton());
  			contentPanel.add(closeButtonLabel);
  
  			closeButtonLabel.addClickHandler(new ClickHandler() {
  				@Override
  				public void onClick(ClickEvent event) {
  					hide();
  				}
  			});
  		}
  
  		// Add the content to the panel.
  		for (Label l : content) {
  			l.addStyleName(ToolTipResource.INSTANCE.css().toolTipLine());
  			contentPanel.add(l);
  		}
  
  		// Finally set position of the tooltip and show it.
  		toolTip.setPopupPosition(left, top);
  		toolTip.show();
  
  	}
docs: Add content to the tooltip and show it with the given parameters.
  
  @param content a list of Labels
  @param left the left position of the tooltip
  @param top the top position of the tooltip