def METHOD_NAME(self):
    defaults = dict(author="Buster", aggregator="Aggregators R US", provider="USA",)
    s = ContentDefaultsSerializer(
        defaults, data=dict(author="Duster", provider="Canada",)
    )
    self.assertTrue(s.is_valid())
    self.assertEqual(
        dict(author="Duster", aggregator="Aggregators R US", provider="Canada",),
        s.save(),
    )