ErrCacheCapacityInvalid signals that capacity of cache is less than 1.

ErrCacheSizeInvalid signals that size of cache is less than 1.

KeyValuePair is a tuple of (key, value).

Cacher provides caching services.

LRUCacheHandler is the interface for LRU cache.

SizedLRUCacheHandler is the interface for size capable LRU cache.

ForEachItem is an iterator callback.