public void ReceiveAdd() { var test = new AsyncTest(); var p = new Person("id"); list.CollectionChanged += (sender, args) => { Assert.AreEqual(NotifyCollectionChangedAction.Add, args.Action); Assert.IsNotNull(args.NewItems); Assert.AreEqual(p, args.NewItems[0]); CollectionAssert.Contains(list, p); test.PassHandler(null, EventArgs.Empty); }; this.server.SendAsync(new BuddyListMessage { ChangeAction = NotifyCollectionChangedAction.Add, People = new[] { p } }); test.Assert(10000); Assert.AreEqual(p, list.FirstOrDefault()); }