def get(self):
        """Get the first public IP address returned by one of the online services."""
        q = queue.Queue()

        for u, j, k in urls:
            t = threading.Thread(target=self._get_ip_public, args=(q, u, j, k))
            t.daemon = True
            t.start()

        timer = Timer(self.timeout)
        ip = None
        while not timer.finished() and ip is None:
            if q.qsize() > 0:
                ip = q.get()

        return ', '.join(set([x.strip() for x in ip.split(',')]))