code: def test_absent_col_error():
      with pytest.raises(ValueError) as value_error:
          df = pd.DataFrame({"a": [1]})
          DFtoVW(
              df=df,
              label=SimpleLabel("a"),
              features=[Feature(col) for col in ["a", "c", "d"]],
          )
      expected = (
          "In 'Feature': column(s) 'c', 'd' not found in dataframe."
      )
      assert expected == str(value_error.value)
  
imports: import pytest
  import pandas
  from vowpalwabbit.dftovw import ContextualbanditLabel, DFtoVW, Feature, MulticlassLabel, MultiLabel, Namespace, SimpleLabel
label_desc: Use image node_id 16 for calling a global function with example usage: test_absent_col_error() without return types