The array must include these keys :
- automatic_cleaning (is automating cleaning necessary)
- tags (are tags supported)
- expired_read (is it possible to read expired cache records
(for doNotTestCacheValidity option for example))
- priority does the backend deal with priority when saving
- infinite_lifetime (is infinite lifetime can work with this backend)
- get_list (is it possible to get the list of cache ids and the complete list of tags)