code: function dequeue(id) {
          var i = qq.indexOf(queue, id),
              max = options.maxConnections,
              nextId;
  
          delete requestData[id];
          queue.splice(i, 1);
  
          if (queue.length >= max && i < max) {
              nextId = queue[max - 1];
              sendRequest(nextId);
          }
      }
docs: Removes element from queue, sends next request