FetchMetadata - Returns the cache metadata for the requested URL.

GetVary - Returns the content from the Vary HTTP header.

PurgeMetadata - Purges the cache metadata for the requested URL.

StorageKey - Returns the cache key for the requested URL.

StoreMetadata - Saves the cache metadata for the requested URL.

TODO: Make it customizable?.

TODO: Make it customizable?.

FreshSuffix - Used for saving a suffix for handling cache stampede.

ErrEmptyValue - Error used when no data is available in Redis.

Object - Contains cache settings and current cached/cacheable object.

URIObj - Holds details about the response.