docs: function (callback) {
        var _this = this;
  
        var guid = _emberMetalUtils.guidFor(this);
  
        _emberViewsSystemJquery.default(window).on('popstate.ember-location-' + guid, function (e) {
          // Ignore initial page load popstate event in Chrome
          if (!popstateFired) {
            popstateFired = true;
            if (_this.getURL() === _this._previousURL) {
              return;
            }
          }
          callback(_this.getURL());
        });
      }