code: def test_nested_min_max() -> None:
      df = pl.DataFrame({"a": [1], "b": [2], "c": [3], "d": [4]})
  
      result = df.with_columns(
          pl.max_horizontal(
              pl.min_horizontal("a", "b"), pl.min_horizontal("c", "d")
          ).alias("t")
      )
  
      expected = pl.DataFrame(
          {"a": [1], "b": [2], "c": [3], "d": [4], "t": [3]}
      )
      assert_frame_equal(result, expected)
  
imports: from __future__ import annotations
  import datetime
  from typing import Any
  import pytest
  import polars
  from polars.testing import assert_frame_equal, assert_series_equal
label_desc: Use image node_id 6 for calling a global function with example usage: test_nested_min_max() without return types