public void Illegal_To_Drive(int illegalAge)
        {
            DrivingAge.Output = new StringWriter();

            DrivingAge.LegalToDrive(illegalAge);

            Assert.That(DrivingAge.Output.ToString(), Is.StringContaining("You are not old enough to legally drive."));
        }
        public void Execute()
        {
            var age = Input.ParseMinimumInt(
                message: "What is your age? ",
                minimum: 0,
                minimumErrorMessage: "Enter a valid age.");

            DrivingAge.LegalToDrive(age);
        }