def clean_semver(cls, version_spec):
        return re.sub(r"([<>=~])\s+?v?", "\\1", version_spec, re.IGNORECASE)
def test_impl():
            df1 = pq.read_table('example.parquet').to_pandas()
            df2 = pq.read_table('example.parquet').to_pandas()
            A3 = pd.concat([df1, df2])
            return (A3.two == 'foo').sum()