public void Given1Return1()
 {
     FizzBuzzController controller = new FizzBuzzController();
     ViewResult result = controller.Index(1) as ViewResult;
     string expected = "1 ";
     string actual = result?.ViewBag.Output;
     Assert.AreEqual(expected, actual);
 }
        public void Given15ReturnFizzBuzz()
        {
            FizzBuzzController controller = new FizzBuzzController();
            ViewResult result = controller.Index(15) as ViewResult;
            string expected = "1 2 Fizz 4 Buzz Fizz 7 8 Fizz Buzz 11 Fizz 13 14 FizzBuzz ";
            string actual = result?.ViewBag.Output;
            Assert.AreEqual(expected, actual);

        }