code: def value(self):
          
          status_code, error_msg, payload = self.check_error()
  
          if not self._status_ok(status_code) and not payload:
              raise CloudUnhandledError("Attempted to decode async request which returned an error.",
                                        reason=error_msg,
                                        status=status_code)
          return self.db[self.async_id]["payload"]
docs: Get the value of the finished async request, if it is available.
  
          :raises CloudUnhandledError: When not checking value of `error` or `is_done` first
          :return: the payload value
          :rtype: str