* This is useful for ParserCache, as it tries to focus on memcached
and use other caches (e.g. mariadb) for the long-tail of less used
content, as setup on WMF. The class uses BagOStuff in a way that is
compatible with this approach.
Bug: T109751
Change-Id: Ia64eb44a9b52a988fde27b468d604d9163bed4b4
