public function delete()
 {
     try {
         $bookmark = new Bookmark($_REQUEST['bookmark_id']);
         $bookmark->delete();
     } catch (\Exception $e) {
         $_SESSION['errorMessages'][] = $e;
     }
     $return_url = !empty($_REQUEST['return_url']) ? $_REQUEST['return_url'] : BASE_URL . '/bookmarks';
     header("Location: {$return_url}");
     exit;
 }