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

  public Set<E> edgesConnecting(EndpointPair<N> endpoints) {
    return delegate().edgesConnecting(endpoints);
  }

  @Override
  public Optional<E> edgeConnecting(N nodeU, N nodeV) {
    return delegate().edgeConnecting(nodeU, nodeV);
  }

  @Override
  public Optional<E> edgeConnecting(EndpointPair<N> endpoints) {
    return delegate().edgeConnecting(endpoints);
  }

  @Override
  @CheckForNull

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)
	}
}

  }

  @Override
  public boolean hasEdgeConnecting(EndpointPair<N> endpoints) {
    checkNotNull(endpoints);
    return isOrderingCompatible(endpoints)
        && hasEdgeConnectingInternal(endpoints.nodeU(), endpoints.nodeV());
  }

  @Override
  @CheckForNull
  public V edgeValueOrDefault(N nodeU, N nodeV, @CheckForNull V defaultValue) {

  public boolean hasEdgeConnecting(EndpointPair<N> endpoints) {
    return delegate().hasEdgeConnecting(endpoints);
  }

  @Override
  @CheckForNull
  public V edgeValueOrDefault(N nodeU, N nodeV, @CheckForNull V defaultValue) {
    return delegate().edgeValueOrDefault(nodeU, nodeV, defaultValue);
  }

  @Override
  @CheckForNull
  public V edgeValueOrDefault(EndpointPair<N> endpoints, @CheckForNull V defaultValue) {

notify_webhook        publish bucket notifications to webhook endpoints
notify_amqp           publish bucket notifications to AMQP endpoints
notify_kafka          publish bucket notifications to Kafka endpoints
notify_mqtt           publish bucket notifications to MQTT endpoints
notify_nats           publish bucket notifications to NATS endpoints
notify_nsq            publish bucket notifications to NSQ endpoints

		t.Run(testCase.s, func(t *testing.T) {
			endpoints, secure, err := parseEndpoints(testCase.s)
			if err != nil && testCase.success {
				t.Errorf("expected to succeed but failed with %s", err)
			}
			if !testCase.success && err == nil {
				t.Error("expected failure but succeeded instead")
			}
			if testCase.success {
				if !reflect.DeepEqual(endpoints, testCase.endpoints) {

			_, ip, _ := strings.Cut(addr, "/")
			ips = append(ips, ip)
		}
		allEndpoints := len(svc.Endpoints)
		healthyEndpoints := 0
		for _, ep := range svc.Endpoints {
			w, f := workloadsByUID[ep.WorkloadUID]
			if !f {
				continue
			}
			if w.Status != "Healthy" {
				continue
			}
			healthyEndpoints++
		}
		endpoints := fmt.Sprintf("%d/%d", healthyEndpoints, allEndpoints)

var (
	defaultHelpPostfix = func(key string) string {
		return config.DefaultHelpPostfix(DefaultKVS, key)
	}

	Help = config.HelpKVS{
		config.HelpKV{
			Key:         Endpoints,
			Description: `comma separated list of etcd endpoints` + defaultHelpPostfix(Endpoints),
			Type:        "csv",
			Sensitive:   true,
		},
		config.HelpKV{
			Key:         PathPrefix,

    edgeToReferenceNode.put(edge, nodeU);
    return true;
  }

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

  @Override
  @CanIgnoreReturnValue
  public boolean removeNode(N node) {
    checkNotNull(node, "node");