setDialOptions(proxy, f.BufListener)
	conn := setupDownstreamConnection(t, proxy)
	downstream := deltaStream(t, conn)
	sendDeltaDownstreamWithNode(t, downstream, model.NodeMetadata{
		Namespace:   "default",
		InstanceIPs: []string{"1.1.1.1"},
	})
}

func deltaStream(t *testing.T, conn *grpc.ClientConn) discovery.AggregatedDiscoveryService_DeltaAggregatedResourcesClient {
	t.Helper()

		select {
		case <-con.InitializedCh():
		default:
			close(con.InitializedCh())
		}
	}()
	firstRequest := true
	for {
		req, err := con.deltaStream.Recv()
		if err != nil {
			if istiogrpc.IsExpectedGRPCError(err) {
				deltaLog.Infof("ADS: %q %s terminated", con.Peer(), con.ID())
				return
			}
			con.ErrorCh() <- err

	// This is included in internal events.
	node *core.Node

	// proxy is the client to which this connection is established.
	proxy *model.Proxy

	// deltaStream is used for Delta XDS. Only one of deltaStream or stream will be set
	deltaStream DeltaDiscoveryStream

	deltaReqChan chan *discovery.DeltaDiscoveryRequest

	s   *DiscoveryServer
	ids []string
}

			doneFunc := func() {
				queue.MarkDone(client)
				<-semaphore
			}

			proxiesQueueTime.Record(time.Since(push.Start).Seconds())
			var closed <-chan struct{}
			if client.deltaStream != nil {
				closed = client.deltaStream.Context().Done()
			} else {
				closed = client.StreamDone()
			}
			go func() {
				pushEv := &Event{
					pushRequest: push,
					done:        doneFunc,
				}