code: def test_skip_nulls_err() -> None:
      df = pl.DataFrame({"foo": [None, None]})
  
      with pytest.raises(
          pl.ComputeError,
          match=r"The output type of the 'apply' function cannot be determined",
      ):
          df.with_columns(
              pl.col("foo").map_elements(lambda x: x, skip_nulls=True)
          )
  
imports: from __future__ import annotations
  import io
  from datetime import date, datetime, time
  from decimal import Decimal
  from typing import TYPE_CHECKING, Any
  import numpy
  import pytest
  import polars
  from polars.datatypes.convert import dtype_to_py_type
  from polars.exceptions import InvalidOperationError
label_desc: Use image node_id 36 for calling a global function with example usage: test_skip_nulls_err() without return types