code: def test_map_rows_error_return_type() -> None:
      df = pl.DataFrame({"a": [[1, 2], [2, 3]], "b": [[4, 5], [6, 7]]})
  
      def combine(row: tuple[Any, ...]) -> list[Any]:
          res = [x + y for x, y in zip(row[0], row[1])]
          return [res]
  
      with pytest.raises(
          pl.ComputeError, match="expected tuple, got list"
      ):
          df.map_rows(combine)
  
file_path: polars/py-polars/tests/unit/operations/map/test_map_rows.py
imports: from __future__ import annotations
  from typing import Any
  import pytest
  import polars
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 4 for calling a global function with example usage: test_map_rows_error_return_type() and returns: list