docs: def convert_string(self, rest):
          """Convert a reST string to an HTML string.
          """
          try:
              html = publish_string(rest, writer_name='html')
          except SystemExit as e:
              err_exit('HTML conversion failed with error: %s' % e.code)
          else:
              if sys.version_info[0] >= 3:
                  return html.decode('utf-8')
              return html