def _create_id(self, set_new=True):
    id_str = "%f%s%f%s" % (
                time.time(),
                id({}),
                random.random(),
                getpid()
            )
    if util.py3k:
        self.id = md5(
                        md5(
                            id_str.encode('ascii')
                        ).hexdigest().encode('ascii')
                    ).hexdigest()
    else:
        self.id = md5(md5(id_str).hexdigest()).hexdigest()

    if set_new:
        self.is_new = True
        self.last_accessed = None
    if self.use_cookies:
        self._set_cookie_values()
        sc = set_new == False
        self._update_cookie_out(set_cookie=sc)