AddressTypeIPv4 = AddressType(v1.IPv4Protocol)

	// AddressTypeIPv6 represents an IPv6 Address.
	AddressTypeIPv6 = AddressType(v1.IPv6Protocol)

	// AddressTypeFQDN represents a FQDN.
	AddressTypeFQDN = AddressType("FQDN")
)

// Endpoint represents a single logical "backend" implementing a service.
type Endpoint struct {
	// addresses of this endpoint. The contents of this field are interpreted

type configs []echo.Config

var _ config.Value = &configs{}

func (c *configs) String() string {
	buf := &bytes.Buffer{}
	for _, cc := range *c {
		_, _ = fmt.Fprintf(buf, "FQDN:     %s\n", cc.ClusterLocalFQDN())
		_, _ = fmt.Fprintf(buf, "Headless: %v\n", cc.Headless)
		_, _ = fmt.Fprintf(buf, "VM:       %v\n", cc.DeployAsVM)
		if cc.DeployAsVM {
			_, _ = fmt.Fprintf(buf, "VMDistro: %s\n", cc.VMDistro)

		},
		{
			name:                     "success: non k8s host not in local cache",
			host:                     "www.bing.com.",
			expectExternalResolution: true,
		},
		{
			name:     "success: k8s host - fqdn",
			host:     "productpage.ns1.svc.cluster.local.",
			expected: a("productpage.ns1.svc.cluster.local.", []netip.Addr{netip.MustParseAddr("9.9.9.9")}),
		},
		{
			name:     "success: k8s host - name.namespace",

	} else {
		epLog.Infof("ready for GRPC endpoint %s", listener.Addr().String())
	}
}

// TODO (hack) we have to send certs OR use xds:///fqdn. We don't know our own fqdn, and even if we did
// we could send traffic to another instance. Instead we look into gRPC internals to authenticate with ourself.

			return true
		}
	case model.Router:
		if config.Kind == kind.ServiceEntry {
			// If config is ServiceEntry, name of the config is service's FQDN
			if features.FilterGatewayClusterConfig && !push.ServiceAttachedToGateway(config.Name, proxy) {
				return false
			}

			hostname := host.Name(config.Name)
			// gateways have default sidecar scopes

			name:    "pure ip6 address",
		},
		{
			service: "istio-pilot.istio-system.svc.cluster.local",
			valid:   true,
			name:    "standard kubernetes FQDN",
		},
		{
			service: "istio-pilot.istio-system.svc.cluster.local:3000",
			valid:   false,
			name:    "standard kubernetes FQDN with port",
		},
		{
			service: "bar/istio.io",
			valid:   true,
			name:    "extension provider service with namespace",
		},
		{

		}
	}
	return nil
}

// ValidateFQDN checks a fully-qualified domain name
func ValidateFQDN(fqdn string) error {
	if err := CheckDNS1123Preconditions(fqdn); err != nil {
		return err
	}
	return ValidateDNS1123Labels(fqdn)
}

// ValidateProxyAddress checks that a network address is well-formed
func ValidateProxyAddress(hostAddr string) error {

		for _, thisI := range i {
			if thisI == thatI {
				found = true
				break
			}
		}
		if !found {
			return false
		}
	}
	return true
}

// Services groups the Instances by FQDN. Each returned element is an Instances
// containing only instances of a single service.
func (i Instances) Services() Services {
	grouped := map[string]Instances{}
	for _, instance := range i {

  @JvmField @RegisterExtension
  val clientTestRule =
    OkHttpClientTestRule().apply {
      recordFrames = true
      // recordSslDebug = true
    }

  // https://tools.ietf.org/html/rfc6066#page-6 specifies a FQDN is required.
  val hostname = "local.host"
  private val handshakeCertificates =
    run {
      // Generate a self-signed cert for the server to serve and the client to trust.
      val heldCertificate =

	return types.NamespacedName{
		Namespace: svc.Attributes.Namespace,
		Name:      svc.Attributes.Name,
	}
}

// serviceClusterSetLocalHostname produces Kubernetes Multi-Cluster Services (MCS) ClusterSet FQDN for a k8s service
func serviceClusterSetLocalHostname(nn types.NamespacedName) host.Name {
	return host.Name(nn.Name + "." + nn.Namespace + "." + "svc" + "." + constants.DefaultClusterSetLocalDomain)
}