// followings as special.
	{mustQuestion("1.0.168.192.in-addr.arpa.", dnsmessage.TypePTR, dnsmessage.ClassINET), dnsmessage.RCodeNameError},
	{mustQuestion("test.", dnsmessage.TypeALL, dnsmessage.ClassINET), dnsmessage.RCodeNameError},
	{mustQuestion("example.com.", dnsmessage.TypeALL, dnsmessage.ClassINET), dnsmessage.RCodeSuccess},

	// Name resolution APIs and libraries should recognize the

					Hdr: dns.RR_Header{Name: domain, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.ttl},
					A:   net.ParseIP(fmt.Sprintf("10.0.0.%d", c)),
				})
			case dns.TypeAAAA:
				// set a long TTL for AAAA
				msg.Answer = append(msg.Answer, &dns.AAAA{
					Hdr:  dns.RR_Header{Name: domain, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.ttl * 10},
					AAAA: net.ParseIP(fmt.Sprintf("fd00::%x", c)),
				})

		r.Hdr = dns.RR_Header{Name: host, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: defaultTTLInSeconds}
		r.AAAA = ip.AsSlice()
		answers[i] = r
	}
	return answers
}

func cname(host string, targetHost string) []dns.RR {
	answer := new(dns.CNAME)
	answer.Hdr = dns.RR_Header{
		Name:   host,
		Rrtype: dns.TypeCNAME,
		Class:  dns.ClassINET,
		Ttl:    defaultTTLInSeconds,
	}
	answer.Target = targetHost

	}
	return nil, 0
}

func cgoLookupCNAME(ctx context.Context, name string) (cname string, err error, completed bool) {
	resources, err := resSearch(ctx, name, int(dnsmessage.TypeCNAME), int(dnsmessage.ClassINET))
	if err != nil {
		return
	}
	cname, err = parseCNAMEFromResources(resources)
	if err != nil {
		return "", err, false
	}
	return cname, nil, true
}

func (r *Resolver) exchange(ctx context.Context, server string, q dnsmessage.Question, timeout time.Duration, useTCP, ad bool) (dnsmessage.Parser, dnsmessage.Header, error) {
	q.Class = dnsmessage.ClassINET
	id, udpReq, tcpReq, err := newRequest(q, ad)
	if err != nil {
		return dnsmessage.Parser{}, dnsmessage.Header{}, errCannotMarshalDNSMessage
	}
	var networks []string
	if useTCP {
		networks = []string{"tcp"}

				}
				if err != nil {
					t.Errorf("Failed to resolve query for %s: %v", tt.host, err)
				} else {
					for _, answer := range res.Answer {
						if answer.Header().Class != dns.ClassINET {
							t.Errorf("expected class INET for all responses, got %+v for host %s", answer.Header(), tt.host)
						}
					}
					if tt.expectExternalResolution {

// A Class is a type of network.
type Class uint16

const (
	// ResourceHeader.Class and Question.Class
	ClassINET   Class = 1
	ClassCSNET  Class = 2
	ClassCHAOS  Class = 3
	ClassHESIOD Class = 4

	// Question.Class
	ClassANY Class = 255
)

var classNames = map[Class]string{
	ClassINET:   "ClassINET",
	ClassCSNET:  "ClassCSNET",
	ClassCHAOS:  "ClassCHAOS",
	ClassHESIOD: "ClassHESIOD",
	ClassANY:    "ClassANY",