Doctrine\ORM\PersistentCollection::__clone
Cleanup internal state of cloned persistent collection.
The following problems have to be prevented: 1. Added entities are added to old PC 2. New collection is not dirty, if reused on other entity nothing changes. 3. Snapshot leads to invalid diffs being generated. 4. Lazy loading grabs entities from old owner object. 5. New collection is connected to old owner and leads to duplicate keys.
Signature
public function __clone()