code: def test_multi_label_error(self, monkeypatch):
      def mock_load(*args, **kwargs):
          return [
              TextClassificationRecord(text="test", multi_label=True)
          ]
  
      monkeypatch.setattr(
          "argilla.labeling.text_classification.weak_labels.load",
          mock_load,
      )
  
      with pytest.raises(MultiLabelError):
          WeakLabels(rules=[lambda x: None], dataset="mock")
  
imports: import sys
  from typing import Callable, List, Optional, Union
  import numpy
  import pandas
  import pytest
  from argilla.client.models import TextClassificationRecord
  from argilla.client.sdk.text_classification.models import CreationTextClassificationRecord, TextClassificationBulkData
  from argilla.labeling.text_classification import WeakLabels, WeakMultiLabels
  from argilla.labeling.text_classification.rule import Rule
  from argilla.labeling.text_classification.weak_labels import DuplicatedRuleNameError, MissingLabelError, MultiLabelError, NoRecordsFoundError, NoRulesFoundError, WeakLabelsBase
  from argilla.server.commons.models import TaskType
  from pandas.testing import assert_frame_equal
  from tests.integration.helpers import SecuredClient
label_desc: Use image node_id 1 for calling the TestWeakLabels obj's underlying member method code with example usage: obj.test_multi_label_error(monkeypatch) and returns: list