if (log.isTraceEnabled()) log.trace("handle ServerConsumerDelegate:" + this.id);
   public boolean handle(Routable r)   {      // deliver the message on a different thread than the core thread that brought it here      try      {         threadPool.execute(new Delivery(callbackHandler, r, log));      }      catch(InterruptedException e)      {         log.warn("Interrupted asynchronous delivery", e);      }      // always NACK the message; it will be asynchronously ACKED later      return false;   }