public String sendRR(Message message, EndPoint[] to, IAsyncCallback cb) {
   String messageId = message.getMessageId();
   callbackMap_.put(messageId, cb);
   for (int i = 0; i < to.length; ++i) {
     sendOneWay(message, to[i]);
   }
   return messageId;
 }
 public IAsyncResult sendRR(Message message, EndPoint to) {
   IAsyncResult iar = new AsyncResult();
   taskCompletionMap_.put(message.getMessageId(), iar);
   sendOneWay(message, to);
   return iar;
 }
 public String sendRR(Message message, EndPoint to, IAsyncCallback cb) {
   String messageId = message.getMessageId();
   callbackMap_.put(messageId, cb);
   sendOneWay(message, to);
   return messageId;
 }