@SuppressWarnings("unchecked")
  public static <K, V> CowMap<K, V> emptyMap()
  {
    return (CowMap<K,V>) EMPTY_MAP;
  }
@Test
  public void testEmptyMap()
  {
    final CowMap<String, String> map = CowUtil.emptyMap();
    Assert.assertTrue(map.isEmpty());
    Assert.assertTrue(map.isReadOnly());

    try
    {
      mutateMap(map);
      Assert.fail("Should have thrown UnsupportedOperationException");
    }
    catch (UnsupportedOperationException e)
    {
      // Expected case
    }

    Assert.assertTrue(CowUtil.<Object, Object>emptyMap().isEmpty());
  }