public void NonNumber_Characters_Throws_Exception()
        {
            Action invalidExecution = () => KaratsubaMultiplication.Calculate("1s", "1");

            Assert.Throws <ArgumentException>(invalidExecution);
        }
        public void Multiply_Complex_Values(string firstNumber, string secondNumber, int expectedResult)
        {
            var result = KaratsubaMultiplication.Calculate(firstNumber, secondNumber);

            Assert.Equal(expectedResult, result);
        }