docs: def read_gtfsr(path, *, from_json=False):
      """
      Given a path (string or Path object) to a GTFSR feed file,
      return the corresponding GTFS feed (FeedMessage instance).
      If ``from_json``, then assume the feed file is in JSON format;
      otherwise, assume the feed file is in Protocol Buffer format.
      """
      path = Path(path)
      feed = gtfs_realtime_pb2.FeedMessage()
  
      with path.open('rb') as src:
          if from_json:
              feed = json_format.Parse(src.read(), feed)
          else:
              feed.ParseFromString(src.read())
  
      return feed