def yaml(self):
        return yaml.dump(self.serialized, default_flow_style=False,
                         encoding=None)
def test_impl(n):
            df = pd.DataFrame({'A': np.ones(n), 'B': np.random.ranf(n)})
            df['moving average'] = df.A.rolling(window=5, center=True).mean()
            return df['moving average'].sum()