if we want to explicitly list cases, we should add more `Doctrine\` options: 

* Doctrine\Orm
* Doctrine\MongoDB
* Doctrine\CouchDB

see http://symfony.com/doc/current/cookbook/doctrine/mapping_model_classes.html and for a concrete example https://github.com/FriendsOfSymfony/FOSUserBundle/tree/master/Doctrine

i guess that was the reason why @dantleech made this a generic match everything. but i see that breaks another feature. adding the other Doctrine\... cases should cover at least the rest of the standard situations.