def save(self):
        tmp_path = self.path + '.tmp'
        with open(tmp_path, 'w') as f:
            f.write(json.dumps(self.body_labels.items()))
        os.rename(tmp_path, self.path)
def test_impl(n):
            S1 = pd.Series(np.ones(n))
            S2 = pd.Series(np.random.ranf(n))
            df = pd.DataFrame({'A': S1, 'B': S2})
            return df.A.sum()