I have passed all but the last (valid special character test) However, I'm having difficulty debugging because there is no example anywhere of what a 'special character' is, and neither can I see the actual test in the test description.

1. Consider to use Assert.True/Assert.False or Assert.That in tests.
2. There is a typo in GivenAVlidPalindromeWithSpecialCharactersOutputShouldBeTrue test case.