assertEquals(0, ms.count(Color.BLUE));
    assertEquals(1, ms.count(Color.YELLOW));
    assertEquals(2, ms.count(Color.RED));
  }

  public void testIllegalCreate() {
    Collection<Color> empty = EnumSet.noneOf(Color.class);
    assertThrows(IllegalArgumentException.class, () -> EnumMultiset.create(empty));
  }

  public void testCreateEmptyWithClass() {