code: def test_serde_keep_dtype_empty_list() -> None:
      s = pl.Series(
          [{"a": None}],
          dtype=pl.Struct([pl.Field("a", pl.List(pl.String))]),
      )
      assert s.dtype == pickle.loads(pickle.dumps(s)).dtype
  
imports: from __future__ import annotations
  import io
  import pickle
  from datetime import datetime, timedelta
  import pytest
  import polars
  from polars import StringCache
  from polars.testing import assert_frame_equal, assert_series_equal
label_desc: Use image node_id 18 for calling a global function with example usage: test_serde_keep_dtype_empty_list() without return types