def test_ThreeCharStringThatHasThreeCharPalindrome(self):
        s = "xxx"
        expected = "xxx"

        actual = maxPalindromeSubstring.find_max_palindrome_substring(s)

        self.assertEqual(expected, actual)
    def test_SixCharStringThatHasFourCharPalindromeInMiddle(self):
        s = "AxxxxB"
        expected = "xxxx"

        actual = maxPalindromeSubstring.find_max_palindrome_substring(s)

        self.assertEqual(expected, actual)
    def test_SingleCharString(self):
        s = "x"
        expected = "x"

        actual = maxPalindromeSubstring.find_max_palindrome_substring(s)

        self.assertEqual(expected, actual)
    def test_FourCharStringThatHasTwoCharPalindromeAtFront(self):
        s = "xxYZ"
        expected = "xx"

        actual = maxPalindromeSubstring.find_max_palindrome_substring(s)

        self.assertEqual(expected, actual)
    def test_StringWithOddLengthPalindromeAsLargest(self):
        s = "ABBAracecarXBA"
        expected = "racecar"

        actual = maxPalindromeSubstring.find_max_palindrome_substring(s)

        self.assertEqual(expected, actual)