code: @Test public void basicObserverTest() throws ExecutionException, InterruptedException {
    OrbitStage stage1=createStage();
    ISomeChatRoom chatRoom=stage1.getReference(ISomeChatRoom.class,"1");
    SomeChatObserver observer=new SomeChatObserver();
    final ISomeChatObserver observerReference=stage1.getObserverReference(ISomeChatObserver.class,observer);
    assertNotNull(observerReference);
    chatRoom.join(observerReference).get();
    chatRoom.sendMessage(observerReference,"bla").get();
    Pair<ISomeChatObserver,String> m=observer.messagesReceived.poll(5,TimeUnit.SECONDS);
    assertNotNull(m);
    assertEquals("bla",m.getRight());
  }
  