protected MessageReference createReference(Routable r)
protected MessageReference createReference(Message m)
   protected MessageReference createReference(Routable r)   {      Object id = r.getMessageID();      messages.remove(id); // TODO Why?      MessageReference ref = new WeakMessageReference((Message)r, this);      messageRefs.put(id, new WeakReference(ref));      messages.put(id, r);      if (log.isTraceEnabled()) { log.trace("added message and reference to memory cache for " + r.getMessageID()); }      return ref;   }