code: public void setText (String text) {
  		if (content instanceof VisLabel) {
  			((VisLabel) content).setText(text);
  		} else {
  			setContent(new VisLabel(text));
  		}
  		pack();
  	}
docs: Changes text tooltip to specified text. If tooltip content is not instance of VisLabel then previous tooltip content
  will be replaced by VisLabel instance.
  @param text next tooltip text