func Region(value string) Instance {
	return newOptionOrSkipIfZero("region", value)
}

func Zone(value string) Instance {
	return newOptionOrSkipIfZero("zone", value)
}

func SubZone(value string) Instance {
	return newOptionOrSkipIfZero("sub_zone", value)
}

func NodeMetadata(meta *model.BootstrapNodeMetadata, rawMeta map[string]any) Instance {

    number: 80
    protocol: HTTP
  resolution: {{.Resolution}}
  endpoints:
  - address: {{.Local}}
    locality: region/zone/subzone
  - address: {{.Remote}}
    locality: notregion/notzone/notsubzone
  {{ if ne .NearLocal "" }}
  - address: {{.NearLocal}}
    locality: "nearregion/zone/subzone"
  {{ end }}
---
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: external-service-locality

		{
			name: "should return correct az if node has only subzone label",
			pods: []*corev1.Pod{pod1, pod2},
			nodes: []*corev1.Node{
				generateNode("node1", map[string]string{label.TopologySubzone.Name: "subzone1"}),
				generateNode("node2", map[string]string{label.TopologySubzone.Name: "subzone2"}),
			},
			wantAZ: map[*corev1.Pod]string{
				pod1: "//subzone1",
				pod2: "//subzone2",
			},
		},
		{

						"topology.kubernetes.io/zone":   "zone1",
						"topology.istio.io/subzone":     "subzone1",
						"topology.istio.io/network":     "network1",
						"topology.istio.io/cluster":     clusterID,
					},
					Address: "1.1.1.1",
					Network: "network1",
					Locality: model.Locality{
						Label:     "region1/zone1/subzone1",
						ClusterID: cluster.ID(clusterID),
					},

	out := make(labels.Instance, len(in)+6)
	for k, v := range in {
		out[k] = v
	}

	region, zone, subzone := SplitLocalityLabel(locality)
	if len(region) > 0 {
		out[LabelTopologyRegion] = region
	}
	if len(zone) > 0 {
		out[LabelTopologyZone] = zone
	}
	if len(subzone) > 0 {
		out[label.TopologySubzone.Name] = subzone
	}
	if len(clusterID) > 0 {
		out[label.TopologyCluster.Name] = clusterID.String()
	}

			name:     "with label",
			label:    "region/zone/subzone-1",
			expected: "region/zone/subzone-1",
		},
		{
			name:     "label with k8s label separator",
			label:    "region" + k8sSeparator + "zone" + k8sSeparator + "subzone-2",
			expected: "region/zone/subzone-2",
		},
		{
			name:     "label with both k8s label separators and slashes",
			label:    "region/zone/subzone.2",
			expected: "region/zone/subzone.2",
		},

      {{- end }}
      {{- if .zone }}
      {{- if .region }}
      ,
      {{- end }}
      "zone": "{{ .zone }}"
      {{- end }}
      {{- if .sub_zone }}
      {{- if or .region .zone }}
      ,
      {{- end }}
      "sub_zone": "{{ .sub_zone }}"
      {{- end }}
    },
    "metadata": {{ .meta_json_str }}
  },
  "layered_runtime": {
      "layers": [
          {

	subzone := node.GetLabels()[label.TopologySubzone.Name]

	if region == "" && zone == "" && subzone == "" {
		return nil
	}

	return &workloadapi.Locality{
		Region:  region,
		Zone:    zone,
		Subzone: subzone,
	}
}

func getWorkloadEntryLocality(p *networkingv1alpha3.WorkloadEntry) *workloadapi.Locality {
	region, zone, subzone := labelutil.SplitLocalityLabel(p.GetLocality())

			ServicePortName: "service-port-name",
			ServiceAccount:  "service-account",
			Network:         "Network",
			Locality: Locality{
				ClusterID: "cluster-id",
				Label:     "region1/zone1/subzone1",
			},
			EndpointPort: 22,
			LbWeight:     100,
			TLSMode:      "mutual",
		},
	}
	differingAddr := exampleInstance.DeepCopy()
	differingAddr.Endpoint.Address = "another-address"

		Template: &v1alpha3.WorkloadEntry{
			Ports:          map[string]uint32{"http": 80},
			Labels:         map[string]string{"app": "a"},
			Network:        "nw0",
			Locality:       "reg0/zone0/subzone0",
			Weight:         1,
			ServiceAccount: "sa-a",
		},
	}
	// A valid Config.
	// This can be modified to have pseudo-random
	// values for more randomization.
	wgA = config.Config{
		Meta: config.Meta{