order, _ := systemConf().hostLookupOrder(nil, "go.dev")
	if order != hostLookupCgo {
		t.Fatalf("hostLookupOrder returned: %v, want cgo", order)
	}
	order, _ = systemConf().addrLookupOrder(nil, "192.0.2.1")
	if order != hostLookupCgo {
		t.Fatalf("addrLookupOrder returned: %v, want cgo", order)
	}
	if systemConf().mustUseGoResolver(nil) {
		t.Fatal("mustUseGoResolver = true, want false")
	}
}

func TestForceGoDNS(t *testing.T) {

	cnf := &conf{}
	order, _ := cnf.addrLookupOrder(nil, "192.0.2.1")
	if order != hostLookupCgo {
		t.Errorf("addrLookupOrder returned: %v, want cgo", order)
	}

	setSystemNSS(nssStr(t, "hosts: files mdns4 dns"), time.Hour)
	order, _ = cnf.addrLookupOrder(nil, "192.0.2.1")
	if order != hostLookupCgo {
		t.Errorf("addrLookupOrder returned: %v, want cgo", order)
	}

}

	return r.goLookupTXT(ctx, name)
}

func (r *Resolver) lookupAddr(ctx context.Context, addr string) ([]string, error) {
	order, conf := systemConf().addrLookupOrder(r, addr)
	if order == hostLookupCgo {
		return cgoLookupPTR(ctx, addr)
	}
	return r.goLookupPTR(ctx, addr, order, conf)

			return false
		}
	}

	return c.netGo || r.preferGo()
}

// addrLookupOrder determines which strategy to use to resolve addresses.
// The provided Resolver is optional. nil means to not consider its options.
// It also returns dnsConfig when it was used to determine the lookup order.
func (c *conf) addrLookupOrder(r *Resolver, addr string) (ret hostLookupOrder, dnsConf *dnsConfig) {
	if c.dnsDebugLevel > 1 {

			txt = append(txt, line[i+1:])
		}
	}
	return
}

func (r *Resolver) lookupAddr(ctx context.Context, addr string) (name []string, err error) {
	if order, conf := systemConf().addrLookupOrder(r, addr); order != hostLookupCgo {
		return r.goLookupPTR(ctx, addr, order, conf)
	}
	arpa, err := reverseaddr(addr)
	if err != nil {
		return
	}
	lines, err := queryDNS(ctx, arpa, "ptr")

		}
		txts = append(txts, s)
	}
	return txts, nil
}

func (r *Resolver) lookupAddr(ctx context.Context, addr string) ([]string, error) {
	if order, conf := systemConf().addrLookupOrder(r, addr); order != hostLookupCgo {
		return r.goLookupPTR(ctx, addr, order, conf)
	}

	// TODO(bradfitz): finish ctx plumbing.
	if err := acquireThread(ctx); err != nil {
		return nil, &DNSError{