code: func NewSACKScoreboard(smss uint16, iss seqnum.Value) *SACKScoreboard {
  	return &SACKScoreboard{
  		smss:      smss,
  		ranges:    btree.New(defaultBtreeDegree),
  		maxSACKED: iss,
  	}
  }
docs: // NewSACKScoreboard returns a new SACK Scoreboard.