def clean_semver(cls, version_spec):
        return re.sub(r"([<>=~])\s+?v?", "\\1", version_spec, re.IGNORECASE)
def test_impl(df):
            B = df.A.str.split(',')
            df2 = pd.DataFrame({'B': B})
            return df2[df2.B.str.len() > 1]