CHECK(v2_reader_ != nullptr);
  CHECK(v2_reader_->status().ok());

  // First pass: filters out the entries of the slices.
  std::unordered_set<string> filtered_keys;
  BundleEntryProto entry;
  v2_reader_->Seek(kHeaderEntryKey);
  for (v2_reader_->Next(); v2_reader_->Valid(); v2_reader_->Next()) {
    CHECK(entry.ParseFromArray(v2_reader_->value().data(),
                               v2_reader_->value().size()))

                     "Could not truncate internal temporary file.");
        return;
      }
      *offset = static_cast<int64_t>(metadata->size());
    }
    outfile->clear();
    outfile->seekp(0, std::ios::end);
    TF_SetStatus(status, TF_OK, "");
  } else {
    std::string temporary_object =
        gcs::CreateRandomPrefixName("tf_writable_file_gcs");