Function wait_late 

fn wait_late(
    shown: Shown,
    serial: u32,
    notice: Notice,
    again: Again,
    pressed: Box<dyn FnOnce(&str) + Send>,
    late: Late,
)

A notice sent and not answered in time: its answer still heard on its connection, however late (LISTEN_LATE), never sent again; answered, it was shown, late (shown_late), and its button counts. Refused late, or its connection gone (the server, or the bus, gone): it may have shown, its record says so still, and it is tried again, the doubt first, while its grace lasts (show_again: the sixth review’s M2).