code: @Test public void twoObserversNoRefTest() throws ExecutionException, InterruptedException {
    OrbitStage stage1=createStage();
    OrbitStage stage2=createStage();
    SomeChatObserver observer1=new SomeChatObserver();
    SomeChatObserver observer2=new SomeChatObserver();
    ISomeChatRoom chatRoom=stage1.getReference(ISomeChatRoom.class,"1");
    ISomeChatRoom chatRoom_r2=stage2.getReference(ISomeChatRoom.class,"1");
    chatRoom.join(observer1).get();
    chatRoom_r2.join(observer2).get();
    chatRoom.sendMessage(observer1,"bla").get();
    Pair<ISomeChatObserver,String> m=observer1.messagesReceived.poll(5,TimeUnit.SECONDS);
    assertNotNull(m);
    assertEquals("bla",m.getRight());
    Pair<ISomeChatObserver,String> m2=observer2.messagesReceived.poll(5,TimeUnit.SECONDS);
    assertNotNull(m2);
    assertEquals("bla",m2.getRight());
  }
  