class PerformanceCachingGoogleCloudStorage extends ForwardingGoogleCloudStorage {

  @Override
  public void close() {
    super.close();

    // Respect close and empty the cache.
    cache.invalidateAll();
  }

  public  PerformanceCachingGoogleCloudStorage(
      GoogleCloudStorage delegate, PerformanceCachingGoogleCloudStorageOptions options);
  @VisibleForTesting  PerformanceCachingGoogleCloudStorage(
      GoogleCloudStorage delegate,
      PrefixMappedItemCache cache);

}