code: func (hc *halfConn) incSeq() {
  	for i := 7; i >= 0; i-- {
  		hc.seq[i]++
  		if hc.seq[i] != 0 {
  			return
  		}
  	}
  
  	// Not allowed to let sequence number wrap.
  	// Instead, must renegotiate before it does.
  	// Not likely enough to bother.
  	panic("TLS: sequence number wraparound")
  }
docs: // incSeq increments the sequence number.