code: def test_streaming_sortedness_propagation_9494() -> None:
      assert (
          pl.DataFrame(
              {
                  "when": [
                      date(2023, 5, 10),
                      date(2023, 5, 20),
                      date(2023, 6, 10),
                  ],
                  "what": [1, 2, 3],
              }
          )
          .lazy()
          .sort("when")
          .group_by_dynamic("when", every="1mo")
          .agg(pl.col("what").sum())
          .collect(streaming=True)
      ).to_dict(as_series=False) == {
          "when": [date(2023, 5, 1), date(2023, 6, 1)],
          "what": [3, 3],
      }
  
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 9 for calling a global function with example usage: test_streaming_sortedness_propagation_9494() without return types