docs: def print_file(self, file_format='ctfile', f=sys.stdout):
          """Print representation of :class:`~ctfile.ctfile.CTfile`.
  
          :param str file_format: Format to use: ``ctfile`` or ``json``.
          :param f: Print to file or stdout.
          :type f: File-like 
          :return: None.
          :rtype: :py:obj:`None`.
          """
          print(self.writestr(file_format=file_format), file=f)