std::vector<int64_t> TensorShapeAsVector(const tensorflow::TensorHandle& handle,
                                         absl::Status* status) {
  std::vector<int64_t> shape;
  int rank = -1;
  *status = handle.NumDims(&rank);
  if (!status->ok()) {
    return shape;
  }
  shape.reserve(rank);
  for (int i = 0; i < rank; ++i) {
    int64_t dim;
    *status = handle.Dim(i, &dim);
    if (!status->ok()) {
      return shape;
    }

		auth = NoAuthMiddleware
	}

	metricsRouter.Handle(prometheusMetricsPathLegacy, auth(metricsHandler()))
	metricsRouter.Handle(prometheusMetricsV2ClusterPath, auth(metricsServerHandler()))
	metricsRouter.Handle(prometheusMetricsV2BucketPath, auth(metricsBucketHandler()))
	metricsRouter.Handle(prometheusMetricsV2NodePath, auth(metricsNodeHandler()))
	metricsRouter.Handle(prometheusMetricsV2ResourcePath, auth(metricsResourceHandler()))

};

// Gets tensor from eager tensor handle.
const Tensor* GetTensorFromHandle(TFE_TensorHandle* h, TF_Status* status) {
  if (h == nullptr) {
    status->status = tensorflow::errors::InvalidArgument("Invalid handle");
    return nullptr;
  }
  tensorflow::TensorHandle* handle =
      tensorflow::TensorHandleFromInterface(tensorflow::unwrap(h));
  if (handle->Type() != TensorHandle::LOCAL) {

 */
@Named
@Singleton
public class DefaultExceptionHandler implements ExceptionHandler {
    @Override
    public ExceptionSummary handleException(Throwable exception) {
        return handle("", exception);
    }

    private ExceptionSummary handle(String message, Throwable exception) {
        String reference = getReference(Collections.newSetFromMap(new IdentityHashMap<>()), exception);

        List<ExceptionSummary> children = null;

	// There is flow control in both directions.
	StreamHandler struct {
		// Handle an incoming request. Initial payload is sent.
		// Additional input packets (if any) are streamed to request.
		// Upstream will block when request channel is full.
		// Response packets can be sent at any time.
		// Any non-nil error sent as response means no more responses are sent.
		Handle StreamHandlerFn

		// Subroute for handler.

  ~AbstractTensorHandle() override {}

 public:
  // Returns tensor dtype.
  virtual tensorflow::DataType DataType() const = 0;

  // Returns the status of the tensor handle. If it is a tfrt::TensorHandle,
  // the tensor handle can be an error and return non-OK status.
  virtual absl::Status TensorHandleStatus() const;

  // Returns tensor shape. If tensor has unknown rank, shape remains untouched.

    setDefault(Dispatcher.class, Dispatcher.immediate());
  }

  private static class DummySubscriber {

    private final EventBus eventBus = new EventBus();

    @Subscribe
    public void handle(@Nullable Object unused) {}

    Subscriber toSubscriber() throws Exception {
      return Subscriber.create(eventBus, this, subscriberMethod());
    }

    SubscriberExceptionContext toContext() {

  // Returns the device which created the handle.
  virtual const char* DeviceName(absl::Status* status) const = 0;
  // Returns the device where the tensor was placed.
  virtual const char* BackingDeviceName(absl::Status* status) const = 0;
  // Returns the device type which created the handle.
  virtual const char* DeviceType(absl::Status* status) const = 0;
  // Returns the device ID which created the handle.

    return nullptr;
  }
  tensorflow::TensorHandle* handle =
      tensorflow::TensorHandleFromInterface(unwrapped_handle);

  if (handle->Type() != tensorflow::TensorHandle::LOCAL) {
    status->status = tensorflow::errors::InvalidArgument(
        "TFE_TensorHandleDevicePointer may not be called on a ",
        handle->TypeString(), " tensor handle.");
    return nullptr;

# Advanced Middleware

In the main tutorial you read how to add [Custom Middleware](../tutorial/middleware.md){.internal-link target=_blank} to your application.

And then you also read how to handle [CORS with the `CORSMiddleware`](../tutorial/cors.md){.internal-link target=_blank}.

In this section we'll see how to use other middlewares.

## Adding ASGI middlewares