code: func (r *response) Send(mt dhcp6.MessageType) (int, error) {
  	p := &dhcp6.Packet{
  		MessageType:   mt,
  		TransactionID: r.req.TransactionID,
  		Options:       r.options,
  	}
  
  	b, err := p.MarshalBinary()
  	if err != nil {
  		return 0, err
  	}
  
  	return r.conn.WriteTo(b, nil, r.remoteAddr)
  }
docs: // Send uses the input message typ, the transaction ID sent by a client,
  // and the options set by Options, to create and send a Packet to the
  // client's address.