code: def test_with_columns_empty() -> None:
      df = pl.DataFrame({"a": [1, 2]})
      result = df.with_columns()
      assert_frame_equal(result, df)
  
imports: import polars
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 2 for calling a global function with example usage: test_with_columns_empty() without return types