code: func ParseMAC48(mac48 string) (MAC48, error) {
  	m, err := net.ParseMAC(mac48)
  	if err != nil || len(m) != 6 {
  		return 0, errors.Reason("invalid MAC-48 address %q", mac48).Err()
  	}
  	bytes := make([]byte, 8)
  	copy(bytes[2:], m)
  	return MAC48(binary.BigEndian.Uint64(bytes)), nil
  }
docs: // ParseMAC48 returns a MAC-48 address from the given string.