throw new IllegalStateException("Cannot find delivery to cancel " + deliveryId);
Delivery del = cancelDeliveryInternal(cancel);   ((Channel)del.getObserver()).deliver(false);
   void cancelDelivery(long deliveryId) throws Throwable   {      Delivery del = (Delivery)deliveries.remove(new Long(deliveryId));            if (del == null)      {         throw new IllegalStateException("Cannot find delivery to cancel " + deliveryId);      }            del.cancel();   }