code: function(id) {
          var q = queues[id], sc;
          if (q.onTimeout) {
              sc = q.context || q;
              q.onTimeout.call(sc, _returnData(q));
          }
  
          _end(id, 'timeout', 'timeout');
      }
docs: hash of queues to manage multiple requests
  @property queues
  @private