code: func (e *endpoint) updateRecentTimestamp(tsVal uint32, maxSentAck seqnum.Value, segSeq seqnum.Value) {
  	if e.sendTSOk && seqnum.Value(e.recentTS).LessThan(seqnum.Value(tsVal)) && segSeq.LessThanEq(maxSentAck) {
  		e.recentTS = tsVal
  	}
  }
docs: // updateRecentTimestamp updates the recent timestamp using the algorithm
  // described in https://tools.ietf.org/html/rfc7323#section-4.3