DRF 如何对匿名用户进行限流？

def get_ident(self, request):    xff = request.META.get('HTTP_X_FORWARDED_FOR')    remote_addr = request.META.get('REMOTE_ADDR')    num_proxies = api_settings.NUM_PROXIES    if num_proxies is not None:        if num_proxies == 0 or xff is None:            return remote_addr        addrs = xff.split(',')        client_addr = addrs[-min(num_proxies, len(addrs))]        return client_addr.strip()    return ''.join(xff.split()) if xff else remote_addr