docs: def read_pickle(fn):
          """Load a GOParser object from a pickle file.
  
          The function automatically detects whether the file is compressed
          with gzip.
  
          Parameters
          ----------
          fn: str
              Path of the pickle file.
  
          Returns
          -------
          `GOParser`
              The GOParser object stored in the pickle file.
          """
          with misc.open_plain_or_gzip(fn, 'rb') as fh:
              parser = pickle.load(fh)
          return parser