cache.put(0, 10);
    cache.put(2, 30);

    fakeTicker.advance(999, MILLISECONDS);
    assertThat(cache.getIfPresent(2)).isEqualTo(30);
    fakeTicker.advance(1, MILLISECONDS);
    assertThat(cache.getIfPresent(2)).isEqualTo(30);
    fakeTicker.advance(1000, MILLISECONDS);
    assertThat(cache.getIfPresent(0)).isNull();
  }

  @Test

  virtual void SetExecutorForThread(EagerExecutor* executor) = 0;

  // Return a list of local tensorflow::Device*.
  // TODO(tfrt-devs): We shouldn't expose legacy device in this API.
  virtual std::vector<tensorflow::Device*> ListLocalTfDevices() = 0;

  // Return a list of all tensorflow::Device*.
  virtual std::vector<tensorflow::Device*> ListAllTfDevices() = 0;

  //===--------------------------------------------------------------------===//

        deferred.length = length;
    }

    /**
     * Advances the buffer index by the specified number of bytes.
     *
     * @param n the number of bytes to advance
     */
    public void advance(final int n) {
        index += n;
        if (index - start > deferred.length) {
            deferred.length = index - start;
        }
    }

    /**

// Controls how to act when we try to run an operation on a given device but
// some input tensors are not on that device.
// LINT.IfChange
// Note: Keep in sync with internal copy of enum in eager/context.h.
typedef enum TFE_ContextDevicePlacementPolicy {
  // Running operations with input tensors on the wrong device will fail.
  TFE_DEVICE_PLACEMENT_EXPLICIT = 0,
  // Copy the tensor to the right device but log a warning.
  TFE_DEVICE_PLACEMENT_WARN = 1,

            final int _identifier_authoritys = 6;
            final int _identifier_authorityi = _dst.index;
            _dst.advance(1 * _identifier_authoritys);
            final int _sub_authorityi = _dst.index;
            _dst.advance(4 * _sub_authoritys);

            _dst = _dst.derive(_identifier_authorityi);
            for (int _i = 0; _i < _identifier_authoritys; _i++) {

  virtual const string& Name() const = 0;

  // Returns the operation's device name.
  //
  // The value returned may be different from the one set by SetDeviceName, but
  // it will be compatible with it: the name will be updated by device placement
  // logic to refer to the specific device chosen.
  //
  // Example: If one calls `op->SetDeviceName("/device:GPU")`, the value

                            void* device_info) = nullptr;

  // Pins the op to `device` based on inputs to `op`. Returns true
  // signifying to pin to the current custom device. Returns false
  // to pin to the physical device.
  //
  // This function is guaranteed to be called only when all of the custom-device
  // inputs are on this device.
  bool (*shall_pin_to_this_device)(const TFE_Op* op, TF_Status* s) = nullptr;

	sudo modprobe loop
	for i in 1 2 3 4; do
		dd if=/dev/zero of=${WORK_DIR}/disks/img.${i} bs=1M count=2000
		device=$(sudo losetup --find --show ${WORK_DIR}/disks/img.${i})
		sudo mkfs.ext4 -F ${device}
		mkdir -p ${WORK_DIR}/mnt/disk${i}/
		sudo mount ${device} ${WORK_DIR}/mnt/disk${i}/
		sudo chown "$(id -u):$(id -g)" ${device} ${WORK_DIR}/mnt/disk${i}/
	done
	set +e
}

        "TFE_TensorHandleDevicePointer may not be called on a ",
        handle->TypeString(), " tensor handle.");
    return nullptr;
  }
  tensorflow::Device* device(handle->device());
  if (device != nullptr) {
    status->status = device->Sync();
    if (!status->status.ok()) {
      return nullptr;
    }
  }
  const tensorflow::Tensor* tensor;
  status->status = handle->Tensor(&tensor);

==============================================================================*/

#ifndef TENSORFLOW_C_EAGER_CUSTOM_DEVICE_TESTUTIL_H_
#define TENSORFLOW_C_EAGER_CUSTOM_DEVICE_TESTUTIL_H_

// A simple logging device to test custom device registration.
#include <memory>

#include "tensorflow/c/c_api.h"
#include "tensorflow/c/eager/c_api.h"
#include "tensorflow/c/eager/c_api_experimental.h"
#include "tensorflow/c/tf_status.h"