def yaml(self):
        return yaml.dump(self.serialized, default_flow_style=False,
                         encoding=None)
def test_impl_2(n):
            df = pd.DataFrame({'A': np.arange(n) + 1.0, 'B': np.random.ranf(n)})
            Ac = df.A.rolling(7).sum()
            return Ac.sum()