def test_str_split_unbox_df(self):
        def test_impl(df):
            return df.A.iloc[0]

        df = pd.DataFrame({'A': ['AB,CC', 'C,ABB,D']})
        df2 = pd.DataFrame({'A': df.A.str.split(',')})
        hpat_func = self.jit(test_impl)
        self.assertEqual(hpat_func(df2), test_impl(df2))