Change-Id: I01c62de23b73e1bac96aede73cd6995df8ff1221
abstract public function delete( $key, $time = 0 );
/**
- * Merge changes into the existing cache value (possibly creating a new one)
+ * Merge changes into the existing cache value (possibly creating a new one).
+ * The callback function returns the new value given the current value (possibly false),
+ * and takes the arguments: (this BagOStuff object, cache key, current value).
*
* @param $key string
* @param $callback closure Callback method to be executed