addrs[i:].shuffleByWeight()
}

// An MX represents a single DNS MX record.
type MX struct {
	Host string
	Pref uint16
}

// byPref sorts MX records by preference
type byPref []*MX

// sort reorders MX records as specified in RFC 5321.
func (s byPref) sort() {
	for i := range s {
		j := randIntn(i + 1)
		s[i], s[j] = s[j], s[i]
	}
	slices.SortFunc(s, func(a, b *MX) int {