def __repr__(self):
        return "<Requirement(package={package}, version='{version}')>".format(
            package=self.package, version=self.version)
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()