docs: protected void handleHoverEvent(Event evt) {
      if(evt.getTarget() instanceof Element) {
        Element e = (Element) evt.getTarget();
        Node next = e.getNextSibling();
        if(next instanceof Element) {
          toggleTooltip((Element) next, evt.getType());
        }
        else {
          LoggingUtil.warning("Tooltip sibling not found.");
        }
      }
      else {
        LoggingUtil.warning("Got event for non-Element?!?");
      }
    }