assertEquals(map1.size(), map2.size());
Iterator<X> iterator1 = map1.get("1").iterator();
Iterator<X> iterator2 = map2.get("1").iterator();
X next1 = iterator1.next();
X next2 = iterator2.next();
assertTrue(next1 instanceof XImpl1);
assertTrue(next2 instanceof XImpl1);
assertNotSame(next1, next2);
next1 = iterator1.next();