code: def test_excel_compound_types(
      engine: Literal["xlsx2csv", "openpyxl", "pyxlsb"],
  ) -> None:
      df = pl.DataFrame(
          {
              "x": [[1, 2], [3, 4], [5, 6]],
              "y": ["a", "b", "c"],
              "z": [9, 8, 7],
          }
      ).select("x", pl.struct(["y", "z"]))
  
      xls = BytesIO()
      df.write_excel(xls, worksheet="data")
  
      xldf = pl.read_excel(xls, sheet_name="data", engine=engine)
      assert xldf.rows() == [
          ("[1, 2]", "{'y': 'a', 'z': 9}"),
          ("[3, 4]", "{'y': 'b', 'z': 8}"),
          ("[5, 6]", "{'y': 'c', 'z': 7}"),
      ]
  
imports: from __future__ import annotations
  import warnings
  from collections import OrderedDict
  from datetime import date, datetime
  from io import BytesIO
  from typing import TYPE_CHECKING, Any, Callable, Literal
  import pytest
  import polars
  import polars.selectors
  from polars.exceptions import NoDataError, ParameterCollisionError
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 18 for calling a global function with example usage: test_excel_compound_types(engine) without return types