code: public function createUrl($attribute, $absolute = false)
      {
          if (($params = $this->params) === null) {
              $request = Yii::$app->getRequest();
              $params = $request instanceof Request ? $request->getQueryParams() : [];
          }
          $params[$this->sortParam] = $this->createSortParam($attribute);
          $params[0] = $this->route === null ? Yii::$app->controller->getRoute() : $this->route;
          $urlManager = $this->urlManager === null ? Yii::$app->getUrlManager() : $this->urlManager;
          if ($absolute) {
              return $urlManager->createAbsoluteUrl($params);
          }
  
          return $urlManager->createUrl($params);
      }
docs: Creates a URL for sorting the data by the specified attribute.
  This method will consider the current sorting status given by [[attributeOrders]].
  For example, if the current page already sorts the data by the specified attribute in ascending order,
  then the URL created will lead to a page that sorts the data by the specified attribute in descending order.
  @param string $attribute the attribute name
  @param bool $absolute whether to create an absolute URL. Defaults to `false`.
  @return string the URL for sorting. False if the attribute is invalid.
  @throws InvalidConfigException if the attribute is unknown
  @see attributeOrders
  @see params