rust-libp2p: MdnsEvent::Expired (ExpiredAddrsIter) is never called

I wrote a small program. I expected that when a node exits, other nodes will receive the MdnsEvent :: Expired event, but this does not happen. I looked at the code for a long time, and I realized that the problem is:

if let Some(ref mut closest_expiration) = self.closest_expiration {
            if let Poll::Ready(now) = Pin::new(closest_expiration).poll(cx) {
                let mut expired = SmallVec::<[(PeerId, Multiaddr); 4]>::new();
                while let Some(pos) = self
                    .discovered_nodes
                    .iter()
                    .position(|(_, _, exp)| *exp < now)
                {
                    let (peer_id, addr, _) = self.discovered_nodes.remove(pos);
                    expired.push((peer_id, addr));
                }
                
                if !expired.is_empty() {
                    let event = MdnsEvent::Expired(ExpiredAddrsIter {
                        inner: expired.into_iter(),
                    });

                    return Poll::Ready(NetworkBehaviourAction::GenerateEvent(event));
                }
            }
        }

i wrapped expired in dbg!

dbg!(expired);

it turned out that it is always empty

[/home/golubevmt/.cargo/registry/src/github.com-1ecc6299db9ec823/libp2p-mdns-0.31.0/src/behaviour.rs:369] &expired = []
[/home/golubevmt/.cargo/registry/src/github.com-1ecc6299db9ec823/libp2p-mdns-0.31.0/src/behaviour.rs:369] &expired = []
[/home/golubevmt/.cargo/registry/src/github.com-1ecc6299db9ec823/libp2p-mdns-0.31.0/src/behaviour.rs:369] &expired = []
[/home/golubevmt/.cargo/registry/src/github.com-1ecc6299db9ec823/libp2p-mdns-0.31.0/src/behaviour.rs:369] &expired = []

i changed `

*exp < now

to

ext  <= &now

and it worked for me

Oct 23 00:47:04.706  INFO p2p_test: Discovered: 12D3KooWSK4J25g3WNFWo8n7DRxNK5Rwz3dsgDdRKHwowDgr1cbR /ip4/192.168.199.16/udp/57229/quic
Oct 23 00:47:04.706  INFO p2p_test: Discovered: 12D3KooWSK4J25g3WNFWo8n7DRxNK5Rwz3dsgDdRKHwowDgr1cbR /ip4/127.0.0.1/udp/57229/quic
[/home/golubevmt/.cargo/registry/src/github.com-1ecc6299db9ec823/libp2p-mdns-0.31.0/src/behaviour.rs:364] exp <= &now = true
[/home/golubevmt/.cargo/registry/src/github.com-1ecc6299db9ec823/libp2p-mdns-0.31.0/src/behaviour.rs:364] exp <= &now = true
Oct 23 00:47:10.711  INFO p2p_test: Expired: 12D3KooWSK4J25g3WNFWo8n7DRxNK5Rwz3dsgDdRKHwowDgr1cbR /ip4/192.168.199.16/udp/57229/quic
Oct 23 00:47:10.712  INFO p2p_test: Expired: 12D3KooWSK4J25g3WNFWo8n7DRxNK5Rwz3dsgDdRKHwowDgr1cbR /ip4/127.0.0.1/udp/57229/quic