cache2.LookupOrCompute("b", &value, compute_func, &status);
  TF_EXPECT_OK(status.status);
  EXPECT_EQ(value, 1);
  EXPECT_EQ(num_compute_calls, 2);
  cache2.LookupOrCompute("c", &value, compute_func, &status);
  TF_EXPECT_OK(status.status);
  EXPECT_EQ(value, 2);
  EXPECT_EQ(num_compute_calls, 3);
  cache2.LookupOrCompute("d", &value, compute_func, &status);

  /// found, call `compute_func`. If `compute_func` set `status` to `TF_OK`,
  /// store a copy of the output parameter in the cache, and another copy in
  /// `value`.
  void LookupOrCompute(const std::string& key, T* value,
                       const ComputeFunc& compute_func, TF_Status* status) {
    if (max_age_ == 0) {
      return compute_func(key, value, status);
    }

    int64_t read = 0;
    if (is_cache_enabled) {
      absl::ReaderMutexLock l(&gcs_file->block_cache_lock);
      GcsFileStat stat;
      gcs_file->stat_cache->LookupOrCompute(
          path, &stat,
          [gcs_file, bucket, object](const std::string& path, GcsFileStat* stat,
                                     TF_Status* status) {