public void ValidateBooleanToBeTrue()
        {
            // Given
            var validator = new BoolValidator(true);

            // When
            validator.BeTrue();

            // Then
            Assert.True(true);
        }
        public void ValidateBooleanToBeTrueViolated()
        {
            // Given
            var validator = new BoolValidator(false);

            // When
            var exception = Assert.Throws <XunitException>(() => validator.BeTrue(because: "that's the bottom line"));

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

            Assert.Equal(
                $"{rn}validator{rn}is \"False\"{rn}but was expected to be true{rn}because that's the bottom line",
                exception.UserMessage);
        }