docs: function DOMWalker_walk(ids, root, waitFunction) {
      if (typeof waitFunction == 'function')
        this._controller.waitFor(waitFunction());
  
      if (!root)
        root = this._controller.window.document.documentElement;
  
      var resultsArray = this._walk(root);
  
      if (typeof this._callbackResults == 'function')
        this._callbackResults(this._controller, resultsArray);
  
      if (ids)
        this._prepareTargetWindows(ids);
    }