def test_created_at_defaults_to_datetime(self):
art = Article("On the nature of foo")
art.save()
assert bool(art.created_at)
assert isinstance(art.created_at, dt.datetime)
def test_get_by_id(self):
art = Article("On the nature of foo")
art.save()
retrieved = Article.get_by_id(art.id)
assert retrieved == art
