docs: def _add_path(dir_name, payload_info_list):
      """Add a key with the path to each payload_info_dict."""
      for payload_info_dict in payload_info_list:
          file_name = payload_info_dict['filename'] or payload_info_dict['pid']
          payload_info_dict['path'] = d1_common.utils.filesystem.gen_safe_path(
              dir_name, 'data', file_name
          )