}

	return s, nil
}

// parseIPv4Slow parses and returns an IPv4 address in dotted quad
// form, e.g. "192.168.0.1". It is slow but easy to read, and the
// reference implementation against which we compare faster
// implementations for correctness.
func parseIPv4Slow(s string) (Addr, error) {
	fs := strings.Split(s, ".")
	if len(fs) != 4 {