code: def test_apply_MultiLabelError(self, log_dataset):
      with pytest.raises(
          MultiLabelError,
          match="For rules that do not return exactly 1 label",
      ):
          WeakLabels(rules=[lambda x: ["a", "b"]], dataset=log_dataset)
  
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 3 for calling the TestWeakLabels obj's underlying member method code with example usage: obj.test_apply_MultiLabelError(log_dataset) without return types