def validate_refresh_token(self, refresh_token, client, request,<EOL>*args, **kwargs):
token = self._tokengetter(refresh_token=refresh_token)<EOL>if token and token.client_id == client.client_id:<EOL><INDENT>request.client_id = token.client_id<EOL>request.user = token.user<EOL>return True<EOL><DEDENT>return False<EOL>
Ensure the token is valid and belongs to the client

        This method is used by the authorization code grant indirectly by
        issuing refresh tokens, resource owner password credentials grant
        (also indirectly) and the refresh token grant.