code: public function clearOld(int $maxLife): void
      {
          $limit = microtime(true) - $maxLife / 1000000;
  
          foreach (self::$files as &$file) {
              if ($file['time'] <= $limit) {
                  $file = null;
              }
          }
  
          self::$files = array_filter(self::$files);
      }
docs: Removes the session older than the specified time from the storage.
  
  @param  int $maxLife The maximum time (in microseconds) that a session file must be kept.
  @return void