if (log.isTraceEnabled()) { log.trace(this + " referencing " + m); }
if (trace) { log.trace(this + " referencing " + m); }
   public MessageReference reference(Message m)   {      if (m.isReliable() && !acceptReliableMessages)      {         throw new IllegalStateException(this + " does not accept reliable messages (" + m + ")");      }            if (log.isTraceEnabled()) { log.trace(this + " referencing " + m); }            MessageHolder holder = (MessageHolder)messages.get(m.getMessageID());            if (holder == null)      {               addMessage(m);      }      else      {         holder.incRefCount();      }                 MessageReference ref = new WeakMessageReference(m, this);      return ref;   }