code: def test_windows_not_cached() -> None:
      ldf = (
          pl.DataFrame(
              [
                  pl.Series("key", ["a", "a", "b", "b"]),
                  pl.Series("val", [2, 2, 1, 3]),
              ]
          )
          .lazy()
          .filter(
              (pl.col("key").cum_count().over("key") == 0)
              | (pl.col("val").shift(1).over("key").is_not_null())
              | (pl.col("val") != pl.col("val").shift(1).over("key"))
          )
      )
      # this might fail if they are cached
      for _ in range(1000):
          ldf.collect()
  
file_path: polars/py-polars/tests/benchmark/test_release.py
imports: import time
  from pathlib import Path
  from typing import cast
  import numpy
  import pytest
  import polars
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 5 for calling a global function with example usage: test_windows_not_cached() without return types