se->deallocate = Deallocate;
  se->host_memory_allocate = HostMemoryAllocate;
  se->host_memory_deallocate = HostMemoryDeallocate;
  se->get_allocator_stats = GetAllocatorStats;
  se->device_memory_usage = DeviceMemoryUsage;
  se->create_stream = CreateStream;
  se->destroy_stream = DestroyStream;
  se->create_stream_dependency = CreateStreamDependency;
  se->get_stream_status = GetStreamStatus;

        "EnablePeerAccessTo is not supported by pluggable device.");
  }
  bool CanEnablePeerAccessTo(StreamExecutor* other) override { return false; }

  bool DeviceMemoryUsage(int64_t* free, int64_t* total) const override {
    return stream_executor_->device_memory_usage(
        &device_, reinterpret_cast<int64_t*>(free),
        reinterpret_cast<int64_t*>(total));
  }

  // Creates a new DeviceDescription object.

  ASSERT_TRUE(optional_stats.has_value());
  AllocatorStats stats = optional_stats.value();
  ASSERT_EQ(stats.bytes_in_use, 123);
}

TEST_F(StreamExecutorTest, DeviceMemoryUsage) {
  se_.device_memory_usage = [](const SP_Device* const device,
                               int64_t* const free,
                               int64_t* const total) -> TF_Bool {
    *free = 45;
    *total = 7;

  // Fills the underlying device memory usage information, if it is
  // available. If it is not available (false is returned), free/total need not
  // be initialized.
  TF_Bool (*device_memory_usage)(const SP_Device* device, int64_t* free,
                                 int64_t* total);

  /*** STREAM CALLBACKS ***/
  // Creates SP_Stream. This call should also allocate stream