def test_concat_str(self):
        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()

        hpat_func = self.jit(test_impl)
        self.assertEqual(hpat_func(), test_impl())
        self.assertEqual(count_array_REPs(), 0)
        self.assertEqual(count_parfor_REPs(), 0)