assertSame(map, ImmutableClassToInstanceMap.copyOf(map));
  }

  public void testOf_zero() {
    assertTrue(ImmutableClassToInstanceMap.of().isEmpty());
  }

  public void testOf_one() {
    ImmutableClassToInstanceMap<Number> map = ImmutableClassToInstanceMap.of(int.class, 1);
    assertEquals(1, map.size());
  }

  public void testCopyOf_map_valid() {