'Deleting a proxy-of-proxy instance should bubble through to its proxy
and non-proxy parents, deleting *all* referring objects.'

def test_delete_proxy_of_proxy(self):

    test_image = self.create_image()
    test_photo = Photo.objects.get(pk=test_image.pk)
    foo_photo = FooPhoto(my_photo=test_photo)
    foo_photo.save()
    Photo.objects.all().delete()
    self.assertEqual(len(Photo.objects.all()), 0)
    self.assertEqual(len(Image.objects.all()), 0)
    self.assertEqual(len(File.objects.all()), 0)
    self.assertEqual(len(FooPhoto.objects.all()), 0)
    self.assertEqual(len(FooFile.objects.all()), 0)
    self.assertEqual(len(FooImage.objects.all()), 0)
