# Functions
NewConcurrentCache returns pointer to ConcurrentCache safe for concurrent use.
NewDefaultCache returns pointer to DefaultCache not safe for concurrent use.
# Variables
ErrMissingKey occurs when cache doesn't have any value under given key.
# Structs
ConcurrentCache is entity that has ability to store and retrieve arbitrary values.
DefaultCache is entity that has ability to store and retrieve arbitrary values.
# Interfaces
Cache is entity that has ability to store/retrieve arbitrary values.