auto gcs_file = static_cast<GCSFile*>(file->plugin_file);
  if (!gcs_file->outfile.is_open()) {
    TF_SetStatus(status, TF_FAILED_PRECONDITION,
                 "The internal temporary file is not writable.");
    return;
  }
  TF_VLog(3, "Append: gs://%s/%s size %u", gcs_file->bucket.c_str(),
          gcs_file->object.c_str(), n);
  gcs_file->sync_need = true;
  gcs_file->outfile.write(buffer, n);
  if (!gcs_file->outfile)