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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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