Details
Description
the UnitOfWork uses ``newInstance`` to get the managed copy but this method does not exist in 2.1.6, thus breaking the code: https://github.com/doctrine/doctrine2/blob/e1647229cd2544bd77f10620e1b95a5781c4a733/lib/Doctrine/ORM/UnitOfWork.php#L1418
This is probably an error when backporting a patch as the method exists in master
Patch at https://github.com/doctrine/doctrine2/pull/276