code: protected function backgroundifyMenu(&$items)
      {
          if (!is_array($items)) {
              return;
          }
          foreach ($items as $k => $v) {
              if (!isset($items[$k]['linkOptions'])) {
                  $items[$k]['linkOptions'] = [];
              }
              if (!isset($items[$k]['linkOptions']['data-background'])) {
                  $items[$k]['linkOptions']['data-handler'] = 'background';
              }
              if (isset($items[$k]['items'])) {
                  $this->backgroundifyMenu($items[$k]['items']);
              }
          }
      }
docs: [[@doctodo method_description:backgroundifyMenu]].
  
  @param [[@doctodo param_type:items]] $items [[@doctodo param_description:items]]
  
  @return [[@doctodo return_type:backgroundifyMenu]] [[@doctodo return_description:backgroundifyMenu]]