module documentation

A simple least-recently-used (LRU) cache.

Class LRUCache A class which manages a cache of entries, removing unused ones.
Class LRUSizeCache An LRUCache that removes things based on the size of the values.
Class _LRUNode This maintains the linked-list which is the lru internals.
Variable _null_key Undocumented
_null_key =

Undocumented