/**
  * Get application version
  *
  * @return int
  */
 public static function get_version()
 {
     if (empty(self::$version)) {
         $filename = application::get(['application', 'path_full']) . (application::is_deployed() ? '../../../deployed' : '../../deployed');
         self::$version = filemtime($filename);
     }
     return self::$version;
 }