Add assertion
Add assertion

Without this, the test is marked as risky because the parent has method
not annotated with @doesNotPerformAssertions, and that is because there
are children that do perform assertions.

jerome-fix/SonataMediaBundle,hug963/SonataMediaBundle,OskarStark/SonataMediaBundle,hug963/SonataMediaBundle,hug963/SonataMediaBundle,hug963/SonataMediaBundle,sonata-project/SonataMediaBundle,jerome-fix/SonataMediaBundle,jerome-fix/SonataMediaBundle,OskarStark/SonataMediaBundle,hug963/SonataMediaBundle,OskarStark/SonataMediaBundle,jerome-fix/SonataMediaBundle,OskarStark/SonataMediaBundle