public void StringDiffCountDifferentSymbolsVeryLargeString()
        {
            string str1            = "start";
            int    maxStringLength = 1073741823;

            while (maxStringLength / str1.Length > 1)
            {
                str1 += str1;
            }
            int actual   = DifferentSymbolMaxLengthCounter.CountDifferentSymbols(str1);
            int expected = str1.Length;

            Assert.AreEqual(actual, expected);
        }
        public void StringDiffCountDifferentSymbolsBorderConditions(string str1, int expected)
        {
            int actual = DifferentSymbolMaxLengthCounter.CountDifferentSymbols(str1);

            Assert.AreEqual(actual, expected);
        }
        public void StringDiffCountDifferentSymbolsNullString()
        {
            string str1 = null;

            DifferentSymbolMaxLengthCounter.CountDifferentSymbols(str1);
        }
        public void StringDiffCountDifferentSymbolsCountingCorrectly(string str1, int expected)
        {
            int actual = DifferentSymbolMaxLengthCounter.CountDifferentSymbols(str1);

            Assert.AreEqual(actual, expected);
        }