def _post_parse_request(self, request, client_id='', **kwargs):
        """
        This is where clients come to refresh their access tokens

        :param request: The request
        :param authn: Authentication info, comes from HTTP header
        :returns:
        """

        request = RefreshAccessTokenRequest(**request.to_dict())

        try:
            keyjar = self.endpoint_context.keyjar
        except AttributeError:
            keyjar = ""

        request.verify(keyjar=keyjar, opponent_id=client_id)

        if "client_id" not in request:  # Optional for refresh access token request
            request["client_id"] = client_id

        logger.debug("%s: %s" % (request.__class__.__name__, sanitize(request)))

        return request
This is where clients come to refresh their access tokens

        :param request: The request
        :param authn: Authentication info, comes from HTTP header
        :returns: