storage, server := newStorage(t)
	defer server.Terminate(t)
	defer storage.Store.DestroyFunc()
	test := genericregistrytest.New(t, storage.Store)
	endpoints := validNewEndpoints()
	endpoints.ObjectMeta = metav1.ObjectMeta{}
	test.TestCreate(
		// valid
		endpoints,
		// invalid
		&api.Endpoints{
			ObjectMeta: metav1.ObjectMeta{Name: "_-a123-a_"},
		},
	)
}

func TestUpdate(t *testing.T) {
	storage, server := newStorage(t)

	}{
		{
			testName:      "no existing endpoints",
			serviceName:   "foo",
			ip:            "1.2.3.4",
			endpointPorts: []corev1.EndpointPort{{Name: "foo", Port: 8080, Protocol: "TCP"}},
			initialState:  nil,
			expectCreate:  makeEndpointsArray("foo", []string{"1.2.3.4"}, []corev1.EndpointPort{{Name: "foo", Port: 8080, Protocol: "TCP"}}),
		},
		{
			testName:      "existing endpoints satisfy",
			serviceName:   "foo",

  public boolean hasEdgeConnecting(EndpointPair<N> endpoints) {
    checkNotNull(endpoints);
    if (!isOrderingCompatible(endpoints)) {
      return false;
    }
    N nodeU = endpoints.nodeU();
    N nodeV = endpoints.nodeV();
    return nodes().contains(nodeU) && successors(nodeU).contains(nodeV);
  }

  /**
   * Throws {@code IllegalArgumentException} if the ordering of {@code endpoints} is not compatible

  /**
   * Removes the edge connecting {@code endpoints}, if it is present.
   *
   * <p>If this graph is directed, {@code endpoints} must be ordered.
   *
   * @return the value previously associated with the edge connecting {@code endpoints}, or null if
   *     there was no such edge.
   * @since 27.1
   */
  @CanIgnoreReturnValue
  @CheckForNull
  V removeEdge(EndpointPair<N> endpoints);

	fs.Int32Var(&o.ConcurrentServiceEndpointSyncs, "concurrent-service-endpoint-syncs", o.ConcurrentServiceEndpointSyncs, "The number of service endpoint syncing operations that will be done concurrently. Larger number = faster endpoint slice updating, but more CPU (and network) load. Defaults to 5.")

var errEtcdUnreachable = errors.New("etcd is unreachable, please check your endpoints")

func etcdErrToErr(err error, etcdEndpoints []string) error {
	if err == nil {
		return nil
	}
	switch err {
	case context.DeadlineExceeded:
		return fmt.Errorf("%w %s", errEtcdUnreachable, etcdEndpoints)
	default:
		return fmt.Errorf("unexpected error %w from etcd, please check your endpoints %s", err, etcdEndpoints)
	}
}

    return backingValueGraph.putEdgeValue(nodeU, nodeV, Presence.EDGE_EXISTS) == null;
  }

  @Override
  public boolean putEdge(EndpointPair<N> endpoints) {
    validateEndpoints(endpoints);
    return putEdge(endpoints.nodeU(), endpoints.nodeV());
  }

  @Override
  public boolean removeNode(N node) {
    return backingValueGraph.removeNode(node);
  }

  @Override

	dropHints := !utilfeature.DefaultFeatureGate.Enabled(features.TopologyAwareHints)
	if dropHints {
		for _, ep := range oldEPS.Endpoints {
			if ep.Hints != nil {
				dropHints = false
				break
			}
		}
	}

	if dropHints {
		for i := range newEPS.Endpoints {
			if dropHints {
				newEPS.Endpoints[i].Hints = nil
			}
		}
	}
}

)

var printEndpointError = func() func(Endpoint, error, bool) {
	var mutex sync.Mutex
	printOnce := make(map[Endpoint]map[string]int)

	return func(endpoint Endpoint, err error, once bool) {
		reqInfo := (&logger.ReqInfo{}).AppendTags("endpoint", endpoint.String())
		ctx := logger.SetReqInfo(GlobalContext, reqInfo)
		mutex.Lock()
		defer mutex.Unlock()

		m, ok := printOnce[endpoint]
		if !ok {
			m = make(map[string]int)

		{SlashSeparator, Endpoint{}, -1, fmt.Errorf("empty or root endpoint is not supported")},
		{`\`, Endpoint{}, -1, fmt.Errorf("empty or root endpoint is not supported")},
		{"c://foo", Endpoint{}, -1, fmt.Errorf("invalid URL endpoint format")},
		{"ftp://foo", Endpoint{}, -1, fmt.Errorf("invalid URL endpoint format")},
		{"http://server/path?location", Endpoint{}, -1, fmt.Errorf("invalid URL endpoint format")},