public async Task Calculate_ShouldThrowDivideByZeroException_WhenDividingByZero()
        {
            ICalculatorAggregate calculator = new CalculatorAggregate();

            await Assert.ThrowsExceptionAsync <DivideByZeroException>(() => calculator.Calculate(
                                                                          new EquationModel
            {
                Param1    = 5,
                Param2    = 0,
                Operation = "/"
            }));
        }
        public async Task Calculate_ShouldReturnCorrectResult_WhenUsingBasicOperations(double param1, double param2, string op, double expectedResult)
        {
            ICalculatorAggregate calculator = new CalculatorAggregate();
            var result = await calculator.Calculate(
                new EquationModel
            {
                Param1    = param1,
                Param2    = param2,
                Operation = op
            });

            Assert.AreEqual <double>(expectedResult, result);
        }