docs: def csv(self, fh):
          """Writes the results data to `fh` in CSV format and returns `fh`.
  
          :param fh: file to write data to
          :type fh: file object
          :rtype: file object
  
          """
          self._matches.to_csv(fh, encoding='utf-8', float_format='%d',
                               index=False)
          return fh