code: def test_map_elements_explicit_list_output_type() -> None:
      out = pl.DataFrame({"str": ["a", "b"]}).with_columns(
          [
              pl.col("str").map_elements(
                  lambda _: pl.Series([1, 2, 3]),
                  return_dtype=pl.List(pl.Int64),
              )
          ]
      )
  
      assert out.dtypes == [pl.List(pl.Int64)]
      assert out.to_dict(as_series=False) == {
          "str": [[1, 2, 3], [1, 2, 3]]
      }
  
imports: from __future__ import annotations
  import json
  from datetime import date, datetime, timedelta
  import numpy
  import pytest
  import polars
  from polars.exceptions import PolarsInefficientMapWarning
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 12 for calling a global function with example usage: test_map_elements_explicit_list_output_type() without return types