// TODO(b/290063184): remove when USM is GA
uint64_t HashCheckpointIndexFile(absl::string_view model_dir) {
  std::string meta_filename = MetaFilename(io::JoinPath(
      model_dir, kSavedModelVariablesDirectory, kSavedModelVariablesFilename));
  std::string data;
  absl::Status read_status =
      ReadFileToString(Env::Default(), meta_filename, &data);
  if (read_status.ok()) {
    return tensorflow::Fingerprint64(data);
  } else {

  // variables are stored in the variables.data-?????-of-????? files.
  const string variables_index_path = io::JoinPath(
      variables_directory, MetaFilename(kSavedModelVariablesFilename));
  TF_ASSIGN_OR_RETURN(
      bool variables_index_exists,
      internal::FileExists(Env::Default(), variables_index_path));
  if (!variables_index_exists) {

        builder.getStringAttr("__tf_saved_model_variables"),
        /*filename=*/
        builder.getStringAttr(io::JoinPath(kSavedModelVariablesDirectory,
                                           kSavedModelVariablesFilename)));
    variable_and_assets.push_back(
        {input_.meta_graph_def().saver_def().filename_tensor_name(),
         variable_filename_op});