code: def test_row_group_size_saturation() -> None:
      df = pl.DataFrame({"a": [1, 2, 3]})
      f = io.BytesIO()
  
      # request larger chunk than rows in df
      df.write_parquet(f, row_group_size=1024)
      f.seek(0)
      assert_frame_equal(pl.read_parquet(f), df)
  
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 17 for calling a global function with example usage: test_row_group_size_saturation() without return types