}{
		{
			"Empty",
			func(ip net.IP) bool { return false },
			nil,
			nil,
		},
		{
			"Reject IPAddr x 2",
			func(ip net.IP) bool { return false },
			[]net.Addr{
				mustParseIPAddr("8.8.8.8"),
				mustParseIPAddr("1000::"),
			},
			nil,
		},
		{
			"Accept IPAddr x 2",
			func(ip net.IP) bool { return true },
			[]net.Addr{
				mustParseIPAddr("8.8.8.8"),

func AddressSet(isValid func(ip net.IP) bool, addrs []net.Addr) sets.Set[string] {
	ips := sets.New[string]()
	for _, a := range addrs {
		var ip net.IP
		switch v := a.(type) {
		case *net.IPAddr:
			ip = v.IP
		case *net.IPNet:
			ip = v.IP
		default:
			continue
		}
		if isValid(ip) {
			ips.Insert(ip.String())
		}
	}
	return ips
}

func hasRoutableIP(network string, ifi *net.Interface) (net.IP, bool) {
	ifat, err := ifi.Addrs()
	if err != nil {
		return nil, false
	}
	for _, ifa := range ifat {
		switch ifa := ifa.(type) {
		case *net.IPAddr:
			if ip, ok := routableIP(network, ifa.IP); ok {
				return ip, true
			}
		case *net.IPNet:
			if ip, ok := routableIP(network, ifa.IP); ok {
				return ip, true
			}
		}
	}
	return nil, false

			}
			wg.Wait()
		})
	}
}

func lookupSlowFast(ctx context.Context, fn func(context.Context, string, string) ([]IPAddr, error), network, host string) ([]IPAddr, error) {
	switch host {
	case "slow6loopback4":
		// Returns a slow IPv6 address, and a local IPv4 address.
		return []IPAddr{
			{IP: ParseIP(slowDst6)},
			{IP: ParseIP("127.0.0.1")},
		}, nil
	default:
		return fn(ctx, network, host)
	}
}

		}
	}
	return allErrs
}

// ValidateIPFromString validates ip address
func ValidateIPFromString(ipaddr string, fldPath *field.Path) field.ErrorList {
	allErrs := field.ErrorList{}
	if netutils.ParseIPSloppy(ipaddr) == nil {
		allErrs = append(allErrs, field.Invalid(fldPath, ipaddr, "ip address is not valid"))
	}
	return allErrs
}

// ValidatePort validates port numbers

		if runtime.GOOS == "windows" && interf.Flags&net.FlagUp == 0 {
			continue
		}

		for _, addr := range addrs {
			var ip net.IP
			switch v := addr.(type) {
			case *net.IPNet:
				ip = v.IP
			case *net.IPAddr:
				ip = v.IP
			}

			ipList = append(ipList, ip)
		}
	}

	return ipList
}

// mustGetLocalIP4 returns IPv4 addresses of localhost.  It panics on error.

		t.Fatalf("%s.  Unable to get IP addresses of this host.", err)
	}

	for _, addr := range addrs {
		var ip net.IP
		switch v := addr.(type) {
		case *net.IPNet:
			ip = v.IP
		case *net.IPAddr:
			ip = v.IP
		}

		if ip.To4() != nil {
			localIP4.Add(ip.String())
		}
	}

	// Filter ipList by IPs those do not start with '127.'.

// IPv4-mapped IPv6 addresses (e.g. ::ffff:1.2.3.4) are not allowed.
// IP addresses with zones (e.g. fe80::1%eth0) are not allowed.
// Leading zeros in IPv4 address octets are not allowed.
//
//	ip(<string>) <IPAddr>
//
// Examples:
//
//	ip('127.0.0.1') // returns an IPv4 address
//	ip('::1') // returns an IPv6 address
//	ip('127.0.0.256') // error
//	ip(':::1') // error
//
// isIP
//

		}
		if len(v6) > 0 {
			addresses = append(addresses, net.JoinHostPort("::1", port))
		}
	}
	for _, ipAddr := range addresses {
		for _, proto := range []string{"udp", "tcp"} {
			proxy, err := newDNSProxy(proto, ipAddr, h)
			if err != nil {
				return nil, err
			}
			h.dnsProxies = append(h.dnsProxies, proxy)

		}
	}

	return h, nil
}

pkg net/http/httptrace, type ClientTrace struct, WroteRequest func(WroteRequestInfo)
pkg net/http/httptrace, type DNSDoneInfo struct
pkg net/http/httptrace, type DNSDoneInfo struct, Addrs []net.IPAddr
pkg net/http/httptrace, type DNSDoneInfo struct, Coalesced bool
pkg net/http/httptrace, type DNSDoneInfo struct, Err error
pkg net/http/httptrace, type DNSStartInfo struct