public void Should_ack_with_provided_delivery_tag_with_multiple_flag() { // Arrange var channel = Substitute.For <IModel>(); channel.IsOpen.Returns(true); var subs = new CompositeSubscription(); var subscription = new Subscription { ConsumerTag = "ConsumerTag", QueueName = "QueueName", SubscriptionName = "SubscriptionName" }; subscription.SetChannel(channel); subs.AddSubscription(subscription); // Action subs.AckAllUpTo("ConsumerTag", 10); // Assert channel.Received().BasicAck(10, true); }