public void testClone() {
    MultiHashMap map = new MultiHashMap();
    map.put("A", "1");
    map.put("A", "2");
    Collection coll = (Collection) map.get("A");
    assertEquals(1, map.size());
    assertEquals(2, coll.size());

    MultiHashMap cloned = (MultiHashMap) map.clone();
    Collection clonedColl = (Collection) cloned.get("A");
    assertNotSame(map, cloned);
    assertNotSame(coll, clonedColl);
    assertEquals(1, map.size());
    assertEquals(2, coll.size());
    assertEquals(1, cloned.size());
    assertEquals(2, clonedColl.size());
    map.put("A", "3");
    assertEquals(1, map.size());
    assertEquals(3, coll.size());
    assertEquals(1, cloned.size());
    assertEquals(2, clonedColl.size());
  }