if (log.isTraceEnabled()) { log.trace("added " + ref + " at the top of the list in memory"); } return;
if (log.isTraceEnabled()) { log.trace("added " + ref + " at the top of the list in memory"); }
   public void addFirst(MessageReference ref) throws Throwable   {      if (log.isTraceEnabled()) { log.trace("adding " + ref + "at the top of the list in memory"); }      if (ref.isReliable() && !acceptReliableMessages)      {         throw new IllegalStateException("Reliable reference " + ref +                                         " cannot be added to non-recoverable state");      }      messageRefs.addFirst(ref, ref.getPriority());      if (log.isTraceEnabled()) { log.trace("added " + ref + " at the top of the list in memory"); }      return;   }