public void TestTryRoutines()
        {
            SynchronizedDictionary <int, string> data =
                new SynchronizedDictionary <int, string>(new Dictionary <int, string>());

            Assert.IsTrue(data.TryAdd(1, "a"));
            Assert.IsFalse(data.TryAdd(1, "a"));

            Assert.IsTrue(data.TryUpdate(1, "a"));
            Assert.IsTrue(data.TryUpdate(1, "c"));
            Assert.IsTrue(data.TryUpdate(1, "d", "c"));
            Assert.IsFalse(data.TryUpdate(1, "f", "c"));
            Assert.AreEqual("d", data[1]);
            Assert.IsTrue(data.TryUpdate(1, "a", data[1]));
            Assert.AreEqual("a", data[1]);
            Assert.IsFalse(data.TryUpdate(2, "b"));

            string val;

            Assert.IsTrue(data.TryRemove(1, out val) && val == "a");
            Assert.IsFalse(data.TryRemove(2, out val));
            Assert.AreNotEqual(val, "a");

            Assert.IsFalse(data.TryUpdate(1, (k, x) => x.ToUpper()));
            data[1] = "a";
            data[1] = "b";
            Assert.IsTrue(data.TryUpdate(1, (k, x) => x.ToUpper()));
            Assert.AreEqual("B", data[1]);
        }