code: func (c *cubicSender) OnConnectionMigration() {
  	c.hybridSlowStart.Restart()
  	c.prr = PrrSender{}
  	c.largestSentPacketNumber = 0
  	c.largestAckedPacketNumber = 0
  	c.largestSentAtLastCutback = 0
  	c.lastCutbackExitedSlowstart = false
  	c.cubic.Reset()
  	c.numAckedPackets = 0
  	c.congestionWindow = c.initialCongestionWindow
  	c.slowstartThreshold = c.initialMaxCongestionWindow
  	c.maxCongestionWindow = c.initialMaxCongestionWindow
  }
docs: // OnConnectionMigration is called when the connection is migrated (?)