code: private function parsePanelSort(PanelRowInterface $row)
      {
          if (!$row->hasElement('sort')) {
              $element = new DefaultSortElementInformation();
              $row->addElement($element);
          }
      }
docs: Add sort element to the panel.
  
  @param PanelRowInterface $row The row to which the element shall get added to.
  
  @return void