public void GetAndSetValue() { PropertySet set = new PropertySet(); Assert.IsNull(set.GetValue("key")); set.SetValue("key", "value"); Assert.AreEqual("value", set.GetValue("key")); set.SetValue("key", "different value"); Assert.AreEqual("different value", set.GetValue("key")); set.SetValue("key", null); Assert.IsNull(set.GetValue("key")); set.Add("key", "value1"); Assert.AreEqual("value1", set.GetValue("key")); }