docs: def _to_zipfile(self, file_generator):
          """Convert files to zip archive.
          :return: None
          :rtype: :py:obj:`None`
          """
          with zipfile.ZipFile(file_generator.to_path, mode="w", compression=zipfile.ZIP_DEFLATED) as outfile:
              for f in file_generator:
                  outpath = self._output_path(f.source, file_generator.to_format, archive=True)
                  outfile.writestr(outpath, f.writestr(file_generator.to_format))