code: public static String getTargetId(DomEvent<?> event) {
  		Element element = getTarget(event);
  		if (element != null) {
  			return element.getId();
  		}
  		return null;
  	}
docs: Return the ID of the DOM element of the mouse event.
  
  @param event
  The mouse event itself.
  @return Returns the ID of the DOM element or null if something went wrong.