docs: def _handle_exception(self, row, exception):
          """
          Logs an exception occurred during transformation of a row.
  
          :param list|dict|() row: The source row.
          :param Exception exception: The exception.
          """
          self._log('Error during processing of line {0:d}.'.format(self._source_reader.row_number))
          self._log(row)
          self._log(str(exception))
          self._log(traceback.format_exc())