def get_user_id(self, user_id, mount_point='app-id', wrap_ttl=None):
        """GET /auth/<mount_point>/map/user-id/<user_id>

        :param user_id:
        :type user_id:
        :param mount_point:
        :type mount_point:
        :param wrap_ttl:
        :type wrap_ttl:
        :return:
        :rtype:
        """
        path = '/v1/auth/{0}/map/user-id/{1}'.format(mount_point, user_id)
        return self._adapter.get(path, wrap_ttl=wrap_ttl).json()