code: def test_group_by_dynamic_overlapping_groups_flat_apply_multiple_5038(
      every: str | timedelta,
      period: str | timedelta,
      time_zone: str | None,
  ) -> None:
      res = (
          (
              pl.DataFrame(
                  {
                      "a": [
                          datetime(2021, 1, 1)
                          + timedelta(seconds=2**i)
                          for i in range(10)
                      ],
                      "b": [float(i) for i in range(10)],
                  }
              )
              .with_columns(pl.col("a").dt.replace_time_zone(time_zone))
              .lazy()
              .set_sorted("a")
              .group_by_dynamic("a", every=every, period=period)
              .agg([pl.col("b").var().sqrt().alias("corr")])
          )
          .collect()
          .sum()
          .to_dict(as_series=False)
      )
  
      assert res["corr"] == pytest.approx([9.148920923684765])
      assert res["a"] == [None]
  
imports: from __future__ import annotations
  from collections import OrderedDict
  from datetime import datetime, timedelta
  from typing import Any
  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_group_by_dynamic_overlapping_groups_flat_apply_multiple_5038(every, period, time_zone) without return types