public void test_if_51_next_infix_is_02()
        {
            // Arrange
            CarRegCheckerUtil cut = new CarRegCheckerUtil();
            int input             = 51;
            int expected          = 02;

            // Act
            int result = cut.GetNextInfix(input);

            // Assert
            Assert.AreEqual(expected, result);
        }
        public void test_case_2()
        {
            // Arrange
            CarRegCheckerUtil cut = new CarRegCheckerUtil();

            int[] input    = { 51, 52, 52, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 };
            int[] expected = { 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 };
            int   result;

            // Act
            foreach (int number in input)
            {
                result = cut.GetNextInfix(number);
                // Assert
                foreach (int expNum in expected)
                {
                    Assert.AreEqual(expNum, result);
                }
            }
        }