public void enqueue_if_transaction_was_specified() { var frame = new BasicFrame("ACK"); frame.Headers["id"] = "aa"; frame.Headers["transaction"] = "sdfsd"; var client = Substitute.For <IStompClient>(); var subscription = Substitute.For <Subscription>(client, "aa"); client.IsFramePending("aa").Returns(true); client.GetSubscription("aa").Returns(subscription); var sut = new AckHandler(); sut.Process(client, frame); client.Received().EnqueueInTransaction("sdfsd", Arg.Any <Action>(), Arg.Any <Action>()); subscription.DidNotReceive().Ack("aa"); }