public function sendto(UdpMessageEvent $event, $message, $flag=0, $raw=false)
    {
        if(($event->sender instanceof Connection) && $event->sender->listener->parser){
            $message = call_user_func([$event->sender->listener->parser, 'encode'], $message, null);
        }
        
        stream_socket_sendto($event->socket, (string)$message, $flag, $event->peer);
    }