code: function finish(type) {
      var p = pending[type],
          callback,
          urls;
  
      if (p) {
        callback = p.callback;
        urls     = p.urls;
  
        urls.shift();
        pollCount = 0;
  
        // If this is the last of the pending URLs, execute the callback and
        // start the next request in the queue (if any).
        if (!urls.length) {
          callback && callback.call(p.context, p.obj);
          pending[type] = null;
          queue[type].length && load(type);
        }
      }
    }
docs: Called when the current pending resource of the specified type has finished
  loading. Executes the associated callback (if any) and loads the next
  resource in the queue.
  
  @method finish
  @param {String} type resource type ('css' or 'js')
  @private