/**
* Test unregister observer.
*/
public void testUnregisterObserver() {
Entity e = new Entity();
Mediator medi = new Mediator();
e.setMediator(medi);
TestObserver t1 = new TestObserver();
e.registerObserver(t1);
TestObserver t2 = new TestObserver();
e.registerObserver(t2);
TestObserver t3 = new TestObserver();
e.registerObserver(t3);
TestObserver t4 = new TestObserver();
e.registerObserver(t4);
TestObserver t5 = new TestObserver();
e.registerObserver(t5);
TestObserver t6 = new TestObserver();
e.registerObserver(t6);
assertTrue(medi.getObserver(e).size() == 6);
e.unregisterObserver(t2);
assertTrue(medi.getObserver(e).size() == 5);
e.unregisterObserver(t5);
assertTrue(medi.getObserver(e).size() == 4);
e.unregisterObserver(t1);
assertTrue(medi.getObserver(e).size() == 3);
List<IObserver<?>> list = medi.getObserver(e);
assertTrue(list.contains(t3));
assertTrue(list.contains(t4));
assertTrue(list.contains(t6));
}