def test_merging_relational_attributes(self):
        assertions = {
            'tags': set(Tag.objects.filter(name__in=['SWC', 'DC', 'LC'])),
            'task_set': set(Task.objects.none()),
            'todoitem_set': set(TodoItem.objects
                                        .filter(title='Find instructors')),
        }

        rv = self.client.post(self.url, data=self.strategy)
        self.assertEqual(rv.status_code, 302)
        self.event_b.refresh_from_db()

        for key, value in assertions.items():
            self.assertEqual(set(getattr(self.event_b, key).all()), value, key)
Merging: ensure relational fields are properly saved/combined.
dataset/ETHPy150Open swcarpentry/amy/workshops/test/test_event.py/TestEventMerging.test_merging_relational_attributes