public void RecursionStringTest_223Return6s()
            {
                // arrange
                List <string> expectedList = new List <string> {
                    "223", "232", "223", "232", "322", "322"
                };
                var expected = String.Join(", ", expectedList.ToArray());

                // act
                string        inStr      = "223";
                List <string> actualList = LCProgram.RecursionString("", inStr, inStr.Length);
                var           actual     = String.Join(", ", actualList.ToArray());

                // assert
                Assert.AreEqual(expected, actual);
            }