public void IsPalindromePermutationTest_ReturnFalse(string str)
        {
            bool result = Question_1_4.IsPalindromePermutation(str);

            Assert.IsFalse(result, $"{str} is palindrome permutation.");

            result = Question_1_4.IsPalindromePermutationAlt1(str);
            Assert.IsFalse(result, $"{str} is palindrome permutation - alternative 1.");

            result = Question_1_4.IsPalindromePermutationAlt2(str);
            Assert.IsFalse(result, $"{str} is palindrome permutation - alternative 2.");
        }