def get_refresh_token_params(self, scope_list=None):
        """ Return the param object for the post() call to get the access_token
        from the refresh_token

        :param code: the refresh token
        :return: a dict with the url, params and header
        """
        if self.refresh_token is None:
            raise AttributeError('No refresh token is defined.')

        params = {
            'grant_type': 'refresh_token',
            'refresh_token': self.refresh_token,
        }

        if scope_list:
            if isinstance(scope_list, list):
                scopes = '+'.join(scope_list)
            else:
                raise AttributeError('scope_list must be a list of scope.')
            params['scope'] = scopes

        return self.__prepare_token_request(params)