public void Add_GivenASingleNumber_ShouldReturnTheGivenNumber(string input)
 {
     var calculator = new Calculator();
     var expected = Convert.ToInt32(input);
     var result = calculator.Add(input);
     Assert.AreEqual(expected,result);
 }
 public void Add_GivenTwoNumbers_ShouldReturnTheSumOfTheGivenNumbers(string input, int expected)
 {
     var calculator = new Calculator();
     var result = calculator.Add(input);
     Assert.AreEqual(expected,result);
 }