Microsoft.Azure.Amqp.Delivery.Add C# (CSharp) Method

        public static void Add(ref Delivery first, ref Delivery last, Delivery delivery)
        {
            Fx.Assert(delivery.Previous == null && delivery.Next == null, "delivery is already in a list");
            if (first == null)
            {
                Fx.Assert(last == null, "last must be null when first is null");
                first = last = delivery;
            }
            else
            {
                last.Next = delivery;
                delivery.Previous = last;
                last = delivery;
            }
        }

 protected void OnReceiveDelivery(Delivery delivery)
 {
     // this is always the next expected delivery id
     this.nextDeliveryId = delivery.DeliveryId + 1;
     if (!delivery.Settled)
     {
         Delivery.Add(ref this.firstUnsettled, ref this.lastUnsettled, delivery);
     }
 }