public void Should_Fail_ForNullableTypes()
        {
            var values = new object[] { (long?)null, null, (Guid?)Guid.Empty, (Guid?)null, Guid.Empty };

            foreach (var item in values)
            {
                var result = new RequiredNoneDefault().IsValid(item);
                Assert.False(result);
            }
        }
        public void Should_Fail_ForDefaults(object defaultValue)
        {
            var result = new RequiredNoneDefault().IsValid(defaultValue);

            Assert.False(result);
        }