def load_installed_version(self):
        installed_packages = get_installed_pypackages()
        if self.package in installed_packages:
            self.version = "=={}".format(
                installed_packages[self.package].version)
def test_impl(n):
            df = pd.DataFrame({'A': np.arange(n)})
            df['B'] = df.A.map(lambda a: 2 * a)
            return df.B.sum()