async fn watch_paths(conn: Connection) -> Result<()> {
    let mut paths = conn.paths();
    let mut stats = BTreeMap::new();
    while conn.close_reason().is_none() {
        tokio::select! {
            _ = conn.closed() => break,
            _ = paths.updated() => {},
        }
        for path in paths.get() {
            stats.insert(path.id(), (path.remote_addr().clone(), path.stats()));
        }
    }
    let mut stats_by_remote = BTreeMap::<TransportAddr, PathStats>::new();
    for (_, (remote_addr, stats)) in stats {
        let value = stats_by_remote.entry(remote_addr).or_default();
        value.rtt += stats.rtt;
        value.sent_packets += stats.sent_packets;
    }
    println!("Path stats:");
    for (remote, stats) in stats_by_remote {
        println!(
            "  {remote:?}: RTT {:?}, {} packets sent",
            stats.rtt, stats.sent_packets
        );
    }

    println!("Path stats in conn:");
    for i in 0..10 {
        let path_id = PathId(i);
        if let Some(stats) = conn.inner.path_stats(path_id) {
            println!(
                "  [{path_id}]: RTT {:?}, {} packets sent",
                stats.rtt, stats.sent_packets
            );
        }
    }
    Ok(())
}