// block forever on
func (con *ProxyConnection) sendDeltaRequest(req *discovery.DeltaDiscoveryRequest) {
	con.deltaRequestsChan.Put(req)
}

// DeltaAggregatedResources is an implementation of Delta XDS API used for proxying between Istiod and Envoy.
// Every time envoy makes a fresh connection to the agent, we reestablish a new connection to the upstream xds

				log.Errorf("failed to send: %v", err)
				return err
			}
		} else {
			log.Errorf("failed to call tap request: %v", err)
			return err
		}
	}
	return nil
}

func (p *tapProxy) DeltaAggregatedResources(downstream DeltaDiscoveryStream) error {
	return fmt.Errorf("not implemented")

	t.Helper()
	adsClient := discovery.NewAggregatedDiscoveryServiceClient(conn)
	downstream, err := adsClient.DeltaAggregatedResources(ctx)
	if err != nil {
		t.Fatal(err)
	}
	return downstream
}

	test.SetForTest(t, &features.DeltaXds, true)
	return NewDeltaXdsTest(t, conn, func(conn *grpc.ClientConn) (DeltaDiscoveryClient, error) {
		xds := discovery.NewAggregatedDiscoveryServiceClient(conn)
		return xds.DeltaAggregatedResources(context.Background())
	})
}

func NewDeltaXdsTest(t test.Failer, conn *grpc.ClientConn,
	getClient func(conn *grpc.ClientConn) (DeltaDiscoveryClient, error),
) *DeltaAdsTest {

		event.Healthy = req.ErrorDetail == nil
		if !event.Healthy {
			event.Message = req.ErrorDetail.Message
		}
		s.WorkloadEntryController.QueueWorkloadEntryHealth(proxy, event)
	}
}

// DeltaAggregatedResources is not implemented.
// Instead, Generators may send only updates/add, with Delete indicated by an empty spec.
// This works if both ends follow this model. For example EDS and the API generator follow this
// pattern.

func (t *mockDeltaXdsServer) StreamAggregatedResources(discovery.AggregatedDiscoveryService_StreamAggregatedResourcesServer) error {
	return nil
}

func (t *mockDeltaXdsServer) DeltaAggregatedResources(delta discovery.AggregatedDiscoveryService_DeltaAggregatedResourcesServer) error {
	return deltaHandler(delta)
}

var testCluster = &cluster.Cluster{
	Name:                 "test-eds",

func (t *testAdscRunServer) StreamAggregatedResources(stream discovery.AggregatedDiscoveryService_StreamAggregatedResourcesServer) error {
	return StreamHandler(stream)
}

func (t *testAdscRunServer) DeltaAggregatedResources(discovery.AggregatedDiscoveryService_DeltaAggregatedResourcesServer) error {
	return nil
}

func TestADSC_Run(t *testing.T) {
	type testCase struct {
		desc                 string
		inAdsc               *ADSC

	if err := c.Dial(); err != nil {
		return fmt.Errorf("dial context: %v", err)
	}

	xds := discovery.NewAggregatedDiscoveryServiceClient(c.conn)
	xdsClient, err := xds.DeltaAggregatedResources(ctx, grpc.MaxCallRecvMsgSize(math.MaxInt32))
	if err != nil {
		return fmt.Errorf("delta stream: %v", err)
	}
	c.sendNodeMeta.Store(true)
	c.xdsClient = xdsClient
	go c.handleRecv()