public void InvalidPrimeNumberChecker()
        {
            List <int> validPrimes = new List <int> {
                1, 4, 6, 8, 9
            };

            foreach (int number in validPrimes)
            {
                var actual = PrimeNumbersHelper.IsPrimeNumber(number);
                Assert.IsFalse(actual, number + " is a prime number");
            }
        }
        public void PrimeNumberChecker()
        {
            List <int> validPrimes = new List <int> {
                2, 3, 5, 7, 11
            };

            foreach (int number in validPrimes)
            {
                var actual = PrimeNumbersHelper.IsPrimeNumber(number);
                Assert.IsTrue(actual, number + " is not a prime number");
            }
        }