def test_can_update_expired_materials(self):
storage = InMemoryStorage()
girl = Materializer(storage=storage)
woots = self.woots_generator()
girl.add_material("test", lambda: next(woots))
girl.run()
expect(storage.items).to_length(1)
expect(storage.items["test"]).to_equal("woot1")
storage.expire("test")
girl.run()
expect(storage.items).to_length(1)
expect(storage.items["test"]).to_equal("woot2")
