Don't use, this does NOT implement valid HTTP caching.
We currently just use this class to cache a bunch of Debian and Ubuntu Repositories as well as the Docker Registry for offline use. The cache does not revalidate any responses, so machines querying the cache for Debian package updates will be stuck in the past until the cache (on disk) is cleared manually. - This is - simply put - the only use case, where using this class makes any sense.