public void CoverTheory(int initialValue, int addition, int expectedValue)
 {
     var calculator = new Calculator(initialValue);
     var result = calculator.Add(addition);
     Assert.Equal(expectedValue, result);
 }
 public void CoverAddition()
 {
     var calculator = new Calculator(23);
     var result = calculator.Add(2);
     Assert.Equal(25, result);
 }