def METHOD_NAME(self):
    """Creating an LTIPassport with both playlist and consumer site should raise an error."""
    consumer_site = ConsumerSiteFactory()
    playlist = PlaylistFactory()
    with self.assertRaises(ValidationError) as context:
        LTIPassport.objects.create(consumer_site=consumer_site, playlist=playlist)
    self.assertEqual(
        context.exception.messages,
        ["You should set either a Consumer Site or a Playlist, but not both."],
    )