/**
* Helper to verify emptiness of a cache object.
* Compare against an array so we get the cache content difference.
*/
protected function assertCacheEmpty( $cache, $msg = 'Cache should be empty' ) {
/**
* Helper to verify emptiness of a cache object.
* Compare against an array so we get the cache content difference.
*/
protected function assertCacheEmpty( $cache, $msg = 'Cache should be empty' ) {