return false;
return;
      public boolean cancel(Delivery d) throws Throwable      {         MessageReference ref = d.getReference();         if (!ref.isReliable())         {            return false; // no cancellation is sent back         }         if (log.isTraceEnabled()) { log.trace(this + " cancelling " + d); }         Address collectorAddress = (Address)ref.removeHeader(REPLICATOR_OUTPUT_COLLECTOR_ADDRESS);         return sendAsynchronousResponse(collectorAddress, ref.getMessageID(),                                         Acknowledgment.CANCELLED);      }