for k, v := range headers.GetRequest().GetSet() {
		if !isAuthorityHeader(k) {
			continue
		}
		if current != "" {
			return fmt.Errorf("authority header cannot be set multiple times: have %q, attempting to set %q", current, v)
		}
		current = v
	}
	for k, v := range headers.GetRequest().GetAdd() {
		if !isAuthorityHeader(k) {
			continue
		}
		if current != "" {