code: def test_multilabel_non_positive_label_error():
      df = pd.DataFrame({"y": [0], "b": [1]})
      with pytest.raises(ValueError) as value_error:
          DFtoVW(
              df=df,
              label=MultiLabel(label="y"),
              features=Feature("b"),
          )
      expected = "In argument 'label' of 'MultiLabel', column 'y' must be >= 1."
      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 27 for calling a global function with example usage: test_multilabel_non_positive_label_error() without return types