### Question:
EventDispatcher { static public void addEventListener(AbstractEventListener listener) { for (Class<? extends Event> type : listener.interest()) { getEntry(type).listeners.addIfAbsent(listener); } }  static void addEventListener(AbstractEventListener listener); static void fireEvent(Event event); static void clear();  }### Answer:
@Ignore @Test public void testAddListener() throws Exception { final AbstractEventListener listener = new MockListener(); int vusers = 1000; final CountDownLatch latch = new CountDownLatch(vusers); for (int i = 0; i < vusers; ++i) { new Thread(new Runnable() { public void run() { latch.countDown(); EventDispatcher.addEventListener(listener); } }).start(); } latch.await(); assertEquals(1, EventDispatcher.LISTENER_HUB.size()); }