public void SetFlagsTest()
 {
     Assert.That(test.SetFlags(TestEnum.Value1, false), Is.EqualTo(TestEnum.Value2));
     Assert.That(test.SetFlags(TestEnum.Value1, true), Is.EqualTo(test));
     Assert.That(test.SetFlags(TestEnum.Value3, false), Is.EqualTo(test));
     Assert.That(test.SetFlags(TestEnum.Value3, true), Is.EqualTo(TestEnum.Value1 | TestEnum.Value2 | TestEnum.Value3));
 }