docs: function () {
      // If this function was not given any arguments, we have nothing to do
      // here.
      if (arguments.length > 0) {
        // Convert `arguments` to an array
        var args = Array.prototype.slice.call(arguments, 0)
        Array.prototype.push.apply(passed_args, args)
      }
      self._iterate_stack(++index, req, passed_args, not_handled_fn)
    }