code: def test_construct_with_null() -> None:
      # Example from https://github.com/pola-rs/polars/issues/7188
      df = pl.from_dicts(
          [{"A": None}, {"A": "foo"}], schema={"A": pl.Categorical}
      )
      assert df.to_series().to_list() == [None, "foo"]
  
      s = pl.Series(
          [{"struct_A": None}],
          dtype=pl.Struct({"struct_A": pl.Categorical}),
      )
      assert s.to_list() == [{"struct_A": None}]
  
imports: from __future__ import annotations
  import contextlib
  import io
  import operator
  from typing import TYPE_CHECKING, Any, Callable, Literal
  import pytest
  import polars
  from polars import StringCache
  from polars.exceptions import CategoricalRemappingWarning, StringCacheMismatchError
  from polars.testing import assert_frame_equal, assert_series_equal
label_desc: Use image node_id 33 for calling a global function with example usage: test_construct_with_null() without return types