holder.incrementInMemoryChannelCount();
   public synchronized MessageReference reference(Message m)   {      if (m.isReliable() && !acceptReliableMessages)      {         throw new IllegalStateException(this + " does not accept reliable messages (" + m + ")");      }            MessageHolder holder = (MessageHolder)messages.get(new Long(m.getMessageID()));            if (holder == null)      {               holder = addMessage(m);      }      MessageReference ref = new SimpleMessageReference(holder, this);      if (trace) { log.trace(this + " generated " + ref + " for " + m); }      return ref;   }