code: func (r *renoState) updateCongestionAvoidance(packetsAcked int) {
  	// Consume the packets in congestion avoidance mode.
  	r.s.sndCAAckCount += packetsAcked
  	if r.s.sndCAAckCount >= r.s.sndCwnd {
  		r.s.sndCwnd += r.s.sndCAAckCount / r.s.sndCwnd
  		r.s.sndCAAckCount = r.s.sndCAAckCount % r.s.sndCwnd
  	}
  }
docs: // updateCongestionAvoidance will update congestion window in congestion
  // avoidance mode as described in RFC5681 section 3.1