def test_manufacturer(self):
        manufacturers = Manufacturer.objects.all()[:2]
        params = {'manufacturer_id': [manufacturers[0].pk, manufacturers[1].pk]}
        self.assertEqual(self.filterset(params, self.queryset).qs.count(), 2)
        params = {'manufacturer': [manufacturers[0].slug, manufacturers[1].slug]}
        self.assertEqual(self.filterset(params, self.queryset).qs.count(), 2)