code: public void install(Duration delay) {
          if(installed != null) {
              installed.unsubscribe();
          }
          installed = events(delay).<Event>map(either -> either.unify(
                  pos -> MouseStationaryEvent.beginAt(node.localToScreen(pos)),
                  stop -> MouseStationaryEvent.end()))
              .subscribe(evt -> Event.fireEvent(node, evt));
      }
docs: Sets up the code to fire a {@code BEGIN} event when the mouse becomes stationary over the node and has not
  moved for the given amount of time ({@code delay}), and to fire a {@code END} event when the stationary
  mouse moves again. Note: any previously installed delays will be removed without creating memory leaks.