public void ValidateGuidNotToBeValue()
        {
            // Given
            var validator = new GuidInverseValidator(Guid.NewGuid());

            // When
            validator.Be(Guid.Empty);

            // Then
            Assert.True(true);
        }
        public void ValidateGuidNotToBeValueViolated()
        {
            // Given
            var validator = new GuidInverseValidator(Guid.Empty);

            // When
            var exception = Assert.Throws <XunitException>(() => validator.Be(Guid.Empty, "that's the bottom line"));

            // Then
            Assert.NotNull(exception);
            var rn = Environment.NewLine;

            Assert.Equal(
                $"{rn}validator{rn}is \"{Guid.Empty}\"{rn}but was expected not to be \"{Guid.Empty}\"{rn}because that's the bottom line",
                exception.UserMessage);
        }