public void GcdByEuclideanAlgorithmWithRecursion_should_trhow_exception_for_zero()
        {
            //arrange
            GcdByEuclideanAlgorithmWithRecursion gcdByEuclideanAlgorithmWithRecursion =
                new GcdByEuclideanAlgorithmWithRecursion();
            int firstNumb  = 0;
            int secondNumb = 10;

            //act
            //assert
            Assert.ThrowsException <System.DivideByZeroException>(() =>
                                                                  gcdByEuclideanAlgorithmWithRecursion.GetGcd(firstNumb, secondNumb));
        }
        GcdByEuclideanAlgorithmWithRecursion_should_return_correct_value_when_first_and_second_numbers_are_equal()
        {
            //arrange
            GcdByEuclideanAlgorithmWithRecursion gcdByEuclideanAlgorithmWithRecursion =
                new GcdByEuclideanAlgorithmWithRecursion();
            int firstNumb  = 10;
            int secondNumb = 10;
            int expected   = 10;

            //act
            int actual = gcdByEuclideanAlgorithmWithRecursion.GetGcd(firstNumb, secondNumb);

            //assert
            Assert.AreEqual(expected, actual, "not equal");
        }