public void BasicTest()
        {
            var stack = CreateStack(1, 4, 5, 3, 2);

            Question3_5.SortStack(stack);
            Validate(stack, 1, 2, 3, 4, 5);

            // Duplicated values
            stack = CreateStack(3, 4, 1, 2, 3);
            Question3_5.SortStack(stack);
            Validate(stack, 1, 2, 3, 3, 4);
        }
 public void InvalidInputTest()
 {
     TestHelpers.AssertExceptionThrown(() => Question3_5.SortStack <int>(null), typeof(ArgumentNullException));
 }