code: def test_lazy_self_join_file_cache_prop_3979(
      df: pl.DataFrame, tmp_path: Path
  ) -> None:
      tmp_path.mkdir(exist_ok=True)
  
      file_path = tmp_path / "small.parquet"
      df.write_parquet(file_path)
  
      a = pl.scan_parquet(file_path)
      b = pl.DataFrame({"a": [1]}).lazy()
      assert a.join(b, how="cross").collect().shape == (3, 17)
      assert b.join(a, how="cross").collect().shape == (3, 17)
  
imports: from __future__ import annotations
  import io
  from datetime import datetime, time, timezone
  from decimal import Decimal
  from typing import TYPE_CHECKING
  import numpy
  import pandas
  import pyarrow
  import pyarrow.dataset
  import pyarrow.parquet
  import pytest
  import polars
  from polars.testing import assert_frame_equal, assert_series_equal
label_desc: Use image node_id 14 for calling a global function with example usage: test_lazy_self_join_file_cache_prop_3979(df, tmp_path) without return types