code: def _cleanup(self):
          
          for filename in os.listdir(self._storage_dir):
              file_path = path.join(self._storage_dir, filename)
              file_stat = os.stat(file_path)
              evaluate = max(file_stat.st_ctime, file_stat.st_mtime)
              if evaluate + self._duration < time.time():
                  LOGGER.debug('Removing stale file: %s', file_path)
                  os.unlink(file_path)
docs: Remove any stale files from the session storage directory