// of block_size.
  std::unique_ptr<ExpiringLRUCache<GcsFileStat>> stat_cache;
  GCSFile(google::cloud::storage::Client&& gcs_client);
  // This constructor is used for testing purpose only.
  GCSFile(google::cloud::storage::Client&& gcs_client, bool compose,
          uint64_t block_size, size_t max_bytes, uint64_t max_staleness,
          uint64_t stat_cache_max_age, size_t stat_cache_max_entries);

TF_CAPI_EXPORT extern void TF_NewWritableFile(const char* filename,
                                              TF_WritableFileHandle** handle,
                                              TF_Status* status);

// Closes the given handle and frees its memory. If there was a problem closing
// the file, it is indicated by status. Memory is freed in any case.
TF_CAPI_EXPORT extern void TF_CloseWritableFile(TF_WritableFileHandle* handle,

    const TF_SessionOptions* session_options, const TF_Buffer* run_options,
    const char* export_dir, const char* const* tags, int tags_len,
    TF_Graph* graph, TF_Buffer* meta_graph_def, TF_Status* status);

// Close a session.
//
// Contacts any other processes associated with the session, if applicable.
// May not be called after TF_DeleteSession().
TF_CAPI_EXPORT extern void TF_CloseSession(TF_Session*, TF_Status* status);

  // 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
  // returned by DeviceName should be "/device:GPU:*" until a particular GPU is
  // chosen for the operation by the device placement logic in the
  // executor. After that, the value returned by DeviceName will be a full

      : filename_(filename), file_(std::move(file)), ops_(ops) {}

  ~ModularWritableFile() override { ops_->cleanup(file_.get()); }

  Status Append(StringPiece data) override;
  Status Close() override;
  Status Flush() override;
  Status Sync() override;
  Status Name(StringPiece* result) const override;
  Status Tell(int64_t* position) override;

 private:
  std::string filename_;

  /// DEFAULT IMPLEMENTATION: No op.
  void (*sync)(const TF_WritableFile* file, TF_Status* status);

  /// Closes `*file`.
  ///
  /// Flushes all buffers and deallocates all resources.
  ///
  /// Calling `close` must not result in calling `cleanup`.
  ///
  /// Core TensorFlow will never call `close` twice.
  void (*close)(const TF_WritableFile* file, TF_Status* status);
} TF_WritableFileOps;