def loads(self, requirements_text):
        lines = re.findall(Requirement.spec_regex,
                           requirements_text,
                           re.MULTILINE)
        for line in lines:
            self.add(Requirement(line[0], "".join(line[1:])))
def test_impl(n):
            df = pd.DataFrame({'A': np.arange(n)})
            df['B'] = df.A.map(lambda a: 2 * a)
            return df.B.sum()