code: def test_empty_duration() -> None:
      s = pl.DataFrame([], {"days": pl.Int32}).select(
          pl.duration(days="days")
      )
      assert s.dtypes == [pl.Duration("us")]
      assert s.shape == (0, 1)
  
file_path: polars/py-polars/tests/unit/functions/as_datatype/test_duration.py
imports: from __future__ import annotations
  from datetime import date, datetime, timedelta
  from typing import TYPE_CHECKING
  import pytest
  import polars
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 1 for calling a global function with example usage: test_empty_duration() without return types