code: def test_boolean_aggs() -> None:
      df = pl.DataFrame({"bool": [True, False, None, True]})
  
      aggs = [
          pl.mean("bool").alias("mean"),
          pl.std("bool").alias("std"),
          pl.var("bool").alias("var"),
      ]
      assert df.select(aggs).to_dict(as_series=False) == {
          "mean": [0.6666666666666666],
          "std": [0.5773502588272095],
          "var": [0.3333333432674408],
      }
  
      assert df.group_by(pl.lit(1)).agg(aggs).to_dict(
          as_series=False
      ) == {
          "literal": [1],
          "mean": [0.6666666666666666],
          "std": [0.5773502691896258],
          "var": [0.33333333333333337],
      }
  
imports: from __future__ import annotations
  from datetime import date, datetime, timedelta
  from typing import TYPE_CHECKING, Any
  import numpy
  import pytest
  import polars
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 2 for calling a global function with example usage: test_boolean_aggs() without return types