NullPointerException.class,
        () -> Maps.<SomeEnum, Long>newEnumMap((Class<MapsTest.SomeEnum>) null));
  }

  public void testEnumMapWithInitialEnumMap() {
    EnumMap<SomeEnum, Integer> original = Maps.newEnumMap(SomeEnum.class);
    original.put(SomeEnum.SOME_INSTANCE, 0);
    EnumMap<SomeEnum, Integer> copy = Maps.newEnumMap(original);
    assertEquals(original, copy);
  }