def test_doesnt_allow_negative_charge(self):
        band = models.WeightBand(charge=D('-0.1'))
        with self.assertRaises(ValidationError) as cm:
            band.full_clean()
        self.assertTrue(cm.exception.message_dict in 'charge')
dataset/ETHPy150Open django-oscar/django-oscar/tests/unit/shipping/model_tests.py/TestWeightBand.test_doesnt_allow_negative_charge/swapped operands of `in`