code: def test_rolling_map_std(dtype: pl.PolarsDataType) -> None:
      s = pl.Series("A", [1.0, 2.0, 9.0, 2.0, 13.0], dtype=dtype)
      result = s.rolling_map(function=lambda s: s.std(), window_size=3)
  
      expected = pl.Series(
          "A", [None, None, 4.358899, 4.041452, 5.567764], dtype=dtype
      )
      assert_series_equal(result, expected)
  
file_path: polars/py-polars/tests/unit/operations/rolling/test_map.py
imports: from __future__ import annotations
  import numpy
  import pytest
  import polars
  from polars.testing import assert_series_equal
label_desc: Use image node_id 4 for calling a global function with example usage: test_rolling_map_std(dtype) without return types