def yaml(self):
        return yaml.dump(self.serialized, default_flow_style=False,
                         encoding=None)
def test_impl():
            df1 = pq.read_table('example.parquet').to_pandas()
            df2 = pq.read_table('example.parquet').to_pandas()
            A3 = pd.concat([df1.two, df2.two])
            return (A3 == 'foo').sum()