'ForeignKey.validate() passes `model` to db_for_read() even if
model_instance=None.'

@override_settings(DATABASE_ROUTERS=[AuthRouter()])
def test_foreign_key_validation_with_router(self):

    mickey = Person.objects.create(name='Mickey')
    owner_field = Pet._meta.get_field('owner')
    self.assertEqual(owner_field.clean(mickey.pk, None), mickey.pk)
