// enable topology aware routing. May contain a maximum of 8 entries.
  // +listType=atomic
  repeated ForZone forZones = 1;
}

// EndpointPort represents a Port used by an EndpointSlice
message EndpointPort {
  // name represents the name of this port. All ports in an EndpointSlice must have a unique name.

			Labels:       labels.Instance{"app": "ratings"},
			Address:      "2.2.2.21",
			EndpointPort: 8080,
		},
	}

	wiDetails1 := &model.WorkloadInstance{
		Name:      "details-1",
		Namespace: "bookinfo-details",
		Endpoint: &model.IstioEndpoint{
			Labels:       labels.Instance{"app": "details"},
			Address:      "2.2.2.21",
			EndpointPort: 9090,
		},
	}

	wiReviews1 := &model.WorkloadInstance{

			Name:     ptr.To("p33"),
			Port:     ptr.To[int32](33),
			Protocol: ptr.To(v1.ProtocolUDP),
		}}
	}
	complexSubset8 := func(eps *discovery.EndpointSlice) {
		eps.AddressType = discovery.AddressTypeIPv4
		eps.Endpoints = []discovery.Endpoint{{
			Addresses: []string{"10.4.4.4"},
			NodeName:  ptr.To(testHostname),
		}}
		eps.Ports = []discovery.EndpointPort{{

  // enable topology aware routing.
  // +listType=atomic
  repeated ForZone forZones = 1;
}

// EndpointPort represents a Port used by an EndpointSlice
// +structType=atomic
message EndpointPort {
  // name represents the name of this port. All ports in an EndpointSlice must have a unique name.

type ForZone struct {
	// name represents the name of the zone.
	Name string `json:"name" protobuf:"bytes,1,name=name"`
}

// EndpointPort represents a Port used by an EndpointSlice
// +structType=atomic
type EndpointPort struct {
	// name represents the name of this port. All ports in an EndpointSlice must have a unique name.

				{
					Service:     tt.service,
					ServicePort: tt.port,
					Endpoint: &model.IstioEndpoint{
						ServicePortName: tt.port.Name,
						Address:         "192.168.1.1",
						EndpointPort:    10001,
						Locality: model.Locality{
							ClusterID: "",
							Label:     "region1/zone1/subzone1",
						},
						Labels:  tt.service.Attributes.Labels,
						TLSMode: model.IstioMutualTLSModeLabel,

	}

	if instance.Endpoint != nil {
		if err := instance.Endpoint.Labels.Validate(); err != nil {
			errs = multierror.Append(errs, err)
		}

		if err := agent.ValidatePort(int(instance.Endpoint.EndpointPort)); err != nil {
			errs = multierror.Append(errs, err)
		}
	}

	port := instance.ServicePort
	if port == nil {
		errs = multierror.Append(errs, fmt.Errorf("missing service port"))

				Protocol: protocol.GRPC, // SetEndpoints hardcodes this
			},
		},
	})
	sd.SetEndpoints(testSvcHost, "istio-system", []*model.IstioEndpoint{
		{
			Address:         "127.0.0.1",
			EndpointPort:    uint32(xdsPort),
			ServicePortName: "grpc-main",
		},
	})
}

// initPersistent creates echo-persistent.test:9999, type GRPC with one drained endpoint
func initPersistent(sd *memory.ServiceDiscovery) {

	// Hack up some instances for each Service
	for _, s := range o.Services {
		i := &model.ServiceInstance{
			Service: s,
			Endpoint: &model.IstioEndpoint{
				Address:      "1.1.1.1",
				EndpointPort: 8080, // service port is 80, target port is 8080
			},
			ServicePort: s.Ports[0],
		}
		cg.MemRegistry.AddInstance(i)
	}
	l := cg.Listeners(cg.SetupProxy(p))
	xdstest.ValidateListeners(t, l)
	return l
}

		// 1. ep.Address can be empty since https://github.com/istio/istio/pull/45150, in this case we will replace it with gateway ip.
		// 2. ep.Address can be uds when EndpointPort = 0
		if ep.Address != "" && ep.EndpointPort != 0 && !netutil.IsValidIPAddress(ep.Address) {
			return false
		}
		// filter out endpoints that don't match the subset
		if !b.subsetLabels.SubsetOf(ep.Labels) {
			return false
		}