code: def test_streaming_with_hconcat(tmp_path: Path) -> None:
      df1 = pl.DataFrame(
          {
              "id": [0, 0, 1, 1, 2, 2],
              "x": [0.0, 1.0, 2.0, 3.0, 4.0, 5.0],
          }
      )
      df1.write_parquet(tmp_path / "df1.parquet")
  
      df2 = pl.DataFrame(
          {
              "y": [6.0, 7.0, 8.0, 9.0, 10.0, 11.0],
          }
      )
      df2.write_parquet(tmp_path / "df2.parquet")
  
      lf1 = pl.scan_parquet(tmp_path / "df1.parquet")
      lf2 = pl.scan_parquet(tmp_path / "df2.parquet")
      query = (
          pl.concat([lf1, lf2], how="horizontal")
          .group_by("id")
          .agg(pl.all().mean())
          .sort(pl.col("id"))
      )
  
      plan_lines = [
          line.strip()
          for line in query.explain(streaming=True).splitlines()
      ]
  
      # Each input of the concatenation should be a streaming section,
      # as these might be streamable even though the horizontal concatenation itself
      # doesn't yet support streaming.
      for i, line in enumerate(plan_lines):
          if line.startswith("PLAN"):
              assert plan_lines[i + 1].startswith(
                  "--- STREAMING"
              ), f"{line} does not contain a streaming section"
  
      result = query.collect(streaming=True)
  
      expected = pl.DataFrame(
          {
              "id": [0, 1, 2],
              "x": [0.5, 2.5, 4.5],
              "y": [6.5, 8.5, 10.5],
          }
      )
  
      assert_frame_equal(result, expected)
  
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 19 for calling a global function with example usage: test_streaming_with_hconcat(tmp_path) without return types