code: func (s *HybridSlowStart) StartReceiveRound(lastSent protocol.PacketNumber) {
  	s.endPacketNumber = lastSent
  	s.currentMinRTT = 0
  	s.rttSampleCount = 0
  	s.started = true
  }
docs: // StartReceiveRound is called for the start of each receive round (burst) in the slow start phase.