Function close_lasting 

fn close_lasting(
    connection: &LocalConnection,
    server: &Proxy<'_, &LocalConnection>,
    replies: &Rc<RefCell<HashMap<u32, Reply>>>,
    unanswered: Option<u32>,
    id: u32,
)

Taken away: by its number; a Notify not answered yet, its answer waited for first (CLOSE_LATE at most: its number), so that it does not stay (the fifth review’s L4); the close of a session goes on meanwhile.