public void ValueOfLongestSubstringWithoutDuplication()
        {
            string expected = "abc";
            string actual   = LongestSubstringWithoutDuplication.Value("abcabcbb");

            Assert.AreEqual(expected, actual);
        }
        public void LengthOfLongestSubstringWithoutDuplication()
        {
            int expected = 3;
            int actual   = LongestSubstringWithoutDuplication.Length("abcabcbb");

            Assert.AreEqual(expected, actual);
        }