code: def df_times2(df: pl.DataFrame) -> pl.DataFrame:
      return df.select(pl.all() * 2)
  
imports: from __future__ import annotations
  import io
  import pickle
  from datetime import datetime, timedelta
  import pytest
  import polars
  from polars import StringCache
  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: df_times2(df) and returns: df