invoke(cmd, args[used-1:])
	base.Exit()
}

// lookupCmd interprets the initial elements of args
// to find a command to run (cmd.Runnable() == true)
// or else a command group that ran out of arguments
// or had an unknown subcommand (len(cmd.Commands) > 0).
// It returns that command and the number of elements of args
// that it took to arrive at that command.
func lookupCmd(args []string) (cmd *base.Command, used int) {
	cmd = base.Go

				_, err := LookupHost(testNODATA)
				return err
			},
		},
		{
			name: "LookupMX NXDOMAIN",
			query: func() error {
				_, err := LookupMX(testNXDOMAIN)
				return err
			},
		},
		{
			name: "LookupMX NODATA",
			query: func() error {
				_, err := LookupMX(testNODATA)
				return err
			},
		},
		{
			name: "LookupNS NXDOMAIN",

// [Resolver.LookupMX].
func LookupMX(name string) ([]*MX, error) {
	return DefaultResolver.LookupMX(context.Background(), name)
}

// LookupMX returns the DNS MX records for the given domain name sorted by preference.
//
// The returned mail server names are validated to be properly
// formatted presentation-format domain names. If the response contains
// invalid names, those records are filtered out and an error

		return "", e
	}
	return dir, nil
}

// lookupGroupName accepts the name of a group and retrieves the group SID.
func lookupGroupName(groupname string) (string, error) {
	sid, _, t, e := syscall.LookupSID("", groupname)
	if e != nil {
		return "", e
	}
	// https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-samr/7b2aeb27-92fc-41f6-8437-deb65d950921#gt_0387e636-5654-4910-9519-1f8326cf5ec0

	if e != nil {
		return nil, e
	}
	defer LocalFree((Handle)(unsafe.Pointer(sid)))
	return sid.Copy()
}

// LookupSID retrieves a security identifier sid for the account
// and the name of the domain on which the account was found.
// System specify target computer to search.
func LookupSID(system, account string) (sid *SID, domain string, accType uint32, err error) {
	if len(account) == 0 {
		return nil, "", 0, EINVAL
	}

		}
		addrs = append(addrs, &SRV{absDomainName(f[5]), uint16(port), uint16(priority), uint16(weight)})
		cname = absDomainName(f[0])
	}
	byPriorityWeight(addrs).sort()
	return
}

func (r *Resolver) lookupMX(ctx context.Context, name string) (mx []*MX, err error) {
	if systemConf().mustUseGoResolver(r) {
		return r.goLookupMX(ctx, name)
	}
	lines, err := queryDNS(ctx, name, "mx")
	if err != nil {

	}
	byPriorityWeight(srvs).sort()
	return absDomainName(target), srvs, nil
}

func (r *Resolver) lookupMX(ctx context.Context, name string) ([]*MX, error) {
	if systemConf().mustUseGoResolver(r) {
		return r.goLookupMX(ctx, name)
	}
	// TODO(bradfitz): finish ctx plumbing.
	if err := acquireThread(ctx); err != nil {

pkg net, method (*Resolver) LookupHost(context.Context, string) ([]string, error)
pkg net, method (*Resolver) LookupIPAddr(context.Context, string) ([]IPAddr, error)
pkg net, method (*Resolver) LookupMX(context.Context, string) ([]*MX, error)
pkg net, method (*Resolver) LookupNS(context.Context, string) ([]*NS, error)
pkg net, method (*Resolver) LookupPort(context.Context, string, string) (int, error)