public void SetVal()
        {
            var dict = new Dictionary<int, string>();
            dict.Add(1, "1");

            dict.SetVal(2, "2");
            Assert.AreEqual("([1,1],[2,2])", dict.Print());
            dict.SetVal(1, "3");
            Assert.AreEqual("([1,3],[2,2])", dict.Print());
        }