public CalculatorResult Subtract(double firstOperand, double secondOperand)
 {
     try
     {
         _calculatorResult.Result       = _calculatorManager.Subtract(firstOperand, secondOperand);
         _calculatorResult.IsSuccessful = true;
     }
     catch (Exception e)
     {
         _calculatorResult.IsSuccessful = false;
         _calculatorResult.ErrorMessage = e.Message.ToString();
     }
     return(_calculatorResult);
 }
        public void GivenSubtract_WhenOperandsAreValid_ThenReturnResult(double firstOperand, double secondOperand, double expectedResult)
        {
            var result = _calculatorManager.Subtract(firstOperand, secondOperand);

            Assert.AreEqual(expectedResult, result);
        }