public static <E extends Enum<E>> FlagSet<E> createFlagSet(
      final Class<E> enumClass,
      final String prefix,
      final EnumSet<E> flags) {
    return new FlagSet<>(enumClass, prefix, flags);
  }
@Test
  public void testInequality() {
    final FlagSet<SimpleEnum> s1 =
        createFlagSet(SimpleEnum.class, KEYDOT, noneOf(SimpleEnum.class));
    final FlagSet<SimpleEnum> s2 =
        createFlagSet(SimpleEnum.class, KEYDOT, SimpleEnum.a, SimpleEnum.b);
    Assertions.assertThat(s1)
        .describedAs("s1 == s2")
        .isNotEqualTo(s2);
  }