public void Calculate_ThrowsIncorrectOperation()
        {
            TestDelegate t = () => SimpleCalculations.Calculate("!", 1, 1);

            Assert.Throws <IncorrectOperationStringException>(t);
        }
        public void Calculate_CalculatesAllPossibleComputations(string operation, double lhs, double rhs, double expectation)
        {
            var result = SimpleCalculations.Calculate(operation, lhs, rhs);

            Assert.That(result, Is.EqualTo(expectation));
        }