EntityManager throws an exception when trying to flush($entity) on a deleted entity

$entity = $em->find("Bug", 1);
$em->remove($entity);
$em->flush($entity);

Throws an exception. Works fine with $em->flush() (No $entity provided).

Would be nice to just flush the deleted entity separate from other entities. This technically works for other operations except remove(). The exception claims that the entity is not mapped. It technically can't be mapped since it's set to be deleted.