public void GivenInteger999_WhenConvertedToRomanNumeral_AssertThatItsCMXCIX()
        {
            string romanNumeral = RomanNumeralCalculator.CalculateRomanNumeral(999);

            Assert.AreEqual(romanNumeral, "CMXCIX");
        }
        public void GivenInteger1_WhenConvertedToRomanNumeral_AssertThatItsI()
        {
            string romanNumeral = RomanNumeralCalculator.CalculateRomanNumeral(1);

            Assert.AreEqual(romanNumeral, "I");
        }
        public void GivenInteger723_WhenConvertedToRomanNumeral_AssertThatItsDCCXXIII()
        {
            string romanNumeral = RomanNumeralCalculator.CalculateRomanNumeral(723);

            Assert.AreEqual(romanNumeral, "DCCXXIII");
        }
        public void GivenInteger90_WhenConvertedToRomanNumeral_AssertThatItsXC()
        {
            string romanNumeral = RomanNumeralCalculator.CalculateRomanNumeral(90);

            Assert.AreEqual(romanNumeral, "XC");
        }
        public void GivenInteger400_WhenConvertedToRomanNumeral_AssertThatItsCD()
        {
            string romanNumeral = RomanNumeralCalculator.CalculateRomanNumeral(400);

            Assert.AreEqual(romanNumeral, "CD");
        }