code: def test_df_item_incorrect_shape_columns() -> None:
      df = pl.DataFrame({"a": [1], "b": [2]})
      with pytest.raises(
          ValueError, match=r".* frame has shape \(1, 2\)"
      ):
          df.item()
  
file_path: polars/py-polars/tests/unit/dataframe/test_item.py
imports: from __future__ import annotations
  import pytest
  import polars
label_desc: Use image node_id 4 for calling a global function with example usage: test_df_item_incorrect_shape_columns() without return types