public void Returns_null_if_enum_value_is_not_contained_in_rejected_set()
        {
            var req = new RejectValuesRequirement <Choices>(new [] { Choices.Yes, Choices.No });

            Assert.Empty(req.Check(Choices.Maybe));
        }
        public void Returns_error_if_enum_value_is_contained_in_rejected_set()
        {
            var req = new RejectValuesRequirement <Choices>(Choices.Yes, Choices.No);

            Assert.NotEmpty(req.Check(Choices.No));
        }
		public void Returns_null_if_enum_value_is_not_contained_in_rejected_set() {
			var req = new RejectValuesRequirement<Choices>(new [] { Choices.Yes, Choices.No });
			Assert.Empty(req.Check(Choices.Maybe));
		}
		public void Returns_error_if_enum_value_is_contained_in_rejected_set() {
			var req = new RejectValuesRequirement<Choices>(Choices.Yes, Choices.No);
			Assert.NotEmpty(req.Check(Choices.No));
		}