// If dirname itself is not readable or does not exist, *undeleted_dir_count is
// set to 1, *undeleted_file_count is set to 0 and an appropriate status (e.g.
// TF_NOT_FOUND) is returned.
//
// If dirname and all its descendants were successfully deleted, TF_OK is
// returned and both error counters are set to zero.
//
// Otherwise, while traversing the tree, undeleted_file_count and
// undeleted_dir_count are updated if an entry of the corresponding type could

// assets) using `run_options`.
//
// Any NULL and non-NULL value combinations for (`run_options, `meta_graph_def`)
// are valid.
//
// - `export_dir` must be set to the path of the exported SavedModel.
// - `tags` must include the set of tags used to identify one MetaGraphDef in
//    the SavedModel.
// - `graph` must be a graph newly allocated with TF_NewGraph().
//

  bool FilesExist(const std::vector<std::string>& files,
                  TransactionToken* token,
                  std::vector<Status>* status) override;
  Status GetChildren(const std::string& dir, TransactionToken* token,
                     std::vector<std::string>* result) override;
  Status GetMatchingPaths(const std::string& pattern, TransactionToken* token,

  /// plugin.
  ///
  /// DEFAULT IMPLEMENTATION: Creates directories one by one. Needs
  /// `path_exists`, `is_directory`, and `create_dir`.
  void (*recursively_create_dir)(const TF_Filesystem* filesystem,
                                 const char* path, TF_Status* status);

  /// Deletes the file specified by `path`.
  ///
  /// Plugins: