def test_old_areas(self):
        nonexistant = 'daguerre/test/nonexistant.png'
        if default_storage.exists(nonexistant):
            default_storage.delete(nonexistant)

        storage_path = self.create_image('100x100.png')
        kwargs = {
            'x1': 0,
            'x2': 10,
            'y1': 0,
            'y2': 10
        }
        area1 = Area.objects.create(storage_path=nonexistant,
                                    **kwargs)
        Area.objects.create(storage_path=storage_path,
                            **kwargs)
        clean = Clean()
        self.assertEqual(list(clean._old_areas()), [area1])
        default_storage.delete(storage_path)
_old_areas should return Areas whose storage_path no longer exists.
dataset/ETHPy150Open littleweaver/django-daguerre/daguerre/tests/unit/test_management.py/CleanTestCase.test_old_areas