code: def test_struct_concat_self_no_rechunk() -> None:
      df = pl.DataFrame([{"A": {"a": 1}}])
      out = pl.concat([df, df], rechunk=False)
      assert out.dtypes == [pl.Struct([pl.Field("a", pl.Int64)])]
      assert out.to_dict(as_series=False) == {"A": [{"a": 1}, {"a": 1}]}
  
imports: from __future__ import annotations
  from dataclasses import dataclass
  from datetime import datetime, time
  from typing import TYPE_CHECKING
  import pandas
  import pyarrow
  import pytest
  import polars
  import polars.selectors
  from polars.testing import assert_frame_equal, assert_series_equal
label_desc: Use image node_id 39 for calling a global function with example usage: test_struct_concat_self_no_rechunk() without return types