code: def test_cut_null_values() -> None:
      s = pl.Series([-1.0, None, 1.0, 2.0, None, 8.0, 4.0])
  
      result = s.cut([1.5, 5.0], labels=["a", "b", "c"])
  
      expected = pl.Series(
          ["a", None, "a", "b", None, "c", "b"], dtype=pl.Categorical
      )
      assert_series_equal(result, expected, categorical_as_str=True)
  
file_path: polars/py-polars/tests/unit/operations/test_cut.py
imports: from __future__ import annotations
  import pytest
  import polars
  from polars.testing import assert_frame_equal, assert_series_equal
label_desc: Use image node_id 5 for calling a global function with example usage: test_cut_null_values() without return types