def tearDown(self):
        super(SimpleInstanceTest, self).tearDown()
        CONF.network_label_regex = self.orig_conf
        CONF.ip_start = None
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()