// Experimental Custom Device.
  //===--------------------------------------------------------------------===//
  virtual CustomDeviceOpHandler& GetCustomDeviceOpHandler() = 0;

  // Returns whether `device_name` is registered as a custom device.
  virtual bool IsCustomDevice(const string& device_name) = 0;

    TFE_CustomDeviceTensorHandleMethods methods, TF_Status* status) {
  tensorflow::ImmediateExecutionContext* context = tensorflow::unwrap(ctx);
  tensorflow::CustomDevice* device = nullptr;
  if (!context->GetCustomDeviceOpHandler().FindCustomDeviceFromName(device_name,
                                                                    &device)) {
    methods.deallocator(data);
    status->status =