code: def test_cross_join_stack() -> None:
      a = pl.Series(np.arange(100_000)).to_frame().lazy()
      t0 = time.time()
      # this should be instant if directly pushed into sink
      # if not the cross join will first fill the stack with all matches of a single chunk
      assert a.join(a, how="cross").head().collect(
          streaming=True
      ).shape == (5, 2)
      t1 = time.time()
      assert (t1 - t0) < 0.5
  
imports: from __future__ import annotations
  import os
  import tempfile
  import time
  from datetime import date
  from pathlib import Path
  from typing import TYPE_CHECKING, Any
  import numpy
  import pytest
  import polars
  from polars.exceptions import PolarsInefficientMapWarning
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 4 for calling a global function with example usage: test_cross_join_stack() without return types