So I have a bad configuration but I don't understand why ... My service `Doctrine\ORM\EntityManager` is defined on `service_manager.aliases` configuration key (by DoctrineORMModule) . 
My initializer is defined on `controllers.initializers` configuration key and I set service name to used at `Doctrine\ORM\EntityManager`. And `$serviceLocator->get()` fails to retrieve service.
I made a mistake ?