use Duration;
/// resend iff:
/// age < 1.0 sec
/// OR age_millis + (id_difference*8) >= 1000
/// Resend iff at least 200 milliseconds have elapsed without the message
/// being acknowledged by the peer.
/// Resend iff at least twenty newer-id payloads have been sent in the meantime
/// without it being acknowledged by the peer.