code: def test_multilabel_with_listlabel_builder():
      df = pd.DataFrame({"y1": [1], "y2": [2], "x": [3]})
      conv = DFtoVW(
          df=df,
          label=[MultiLabel("y1"), MultiLabel("y2")],
          features=Feature("x"),
      )
      first_line = conv.convert_df()[0]
      assert first_line == "1,2 | x:3"
  
imports: import pytest
  import pandas
  from vowpalwabbit.dftovw import ContextualbanditLabel, DFtoVW, Feature, MulticlassLabel, MultiLabel, Namespace, SimpleLabel
label_desc: Use image node_id 25 for calling a global function with example usage: test_multilabel_with_listlabel_builder() without return types