public async Task register_single_delegate_for_notification_expect_message_processing() { var client = new MockQueueObserverClient(); client.RegisterForNotificationOf <GeneralMessage>(async(m) => { if (m is GeneralMessage gMessage) { gMessage.CorrellationId += 1; } await Task.FromResult(true); }); var message = new GeneralMessage { CorrellationId = 1 }; await client.Process(message); Assert.AreEqual(2, message.CorrellationId, "The message was not properly processed through the IQueueObserverClient"); }