def test_get_prep_value_convert(self):
        field = StringSetField('testing')

        self.assertEqual(field.get_prep_value(set(["A", "B", "C"])), '["A", "B", "C"]')

        with self.assertRaises(ValueError):
            field.get_prep_value(5)
    def test_get_prep_value_convert(self):
        field = StringSetField('testing')

        self.assertEqual(field.get_prep_value(set(["A", "B", "C"])), 'A,B,C')
        self.assertEqual(field.get_prep_value(set(["C", "B", "A"])), 'A,B,C')

        with self.assertRaises(ValueError):
            field.get_prep_value(5)