public void WithMaybe_non_equal_invalid()
        {
            var m1 = new WithMaybe(Maybe<DateTime>.Empty);
            var m2 = new WithMaybe(SystemUtil.UtcNow);

            ModelAssert.AreNotEqual(m1, m2);
        }
        public void WithMaybe_non_equal_invalid()
        {
            var m1 = new WithMaybe(Maybe <DateTime> .Empty);
            var m2 = new WithMaybe(SystemUtil.UtcNow);

            ModelAssert.AreNotEqual(m1, m2);
        }