public void Dictionary_RemoveExisting() { string cacheKey = "Dictionary_RemoveExisting"; handler.Remove(cacheKey); List <Item> items = GetNewItems(10); handler.Register(cacheKey, new Func <IDictionary <object, Item> >(() => items.ToDictionary(new Func <Item, object>(x => x.ID))), TimeSpan.FromMinutes(30)); //replace existing key var newItem = new Item() { ID = 1, Count = 400, Name = "New Name" }; handler.DictionaryRemove(cacheKey, 1); var cachedItem = handler.DictionaryRetrieve <int, Item>(cacheKey, 1); Assert.IsNull(cachedItem); handler.Remove(cacheKey); }