class_docstr: Test the Aggregator class.
class_docstr_tok: ["Test","the","Aggregator","class","."]
code: def test_invalid_method(self):
      with pytest.raises(ValueError) as e:
          _ = ml_scorer.Aggregator(method="invalid_method")
          assert (
              "Invalid aggregation method specified: 'invalid_method'"
              in str(e.value)
          ), "String constructor has limited options"
  
      with pytest.raises(TypeError) as e:
          _ = ml_scorer.Aggregator(method=1)
          assert "Expected callable method" in str(
              e.value
          ), "Non-callable methods are not valid"
  
imports: import itertools
  import typing
  import numpy
  import pytest
  import sklearn
  from hypothesis import given, settings
  from hypothesis import strategies
  from hypothesis.strategies import composite
  from hypothesis.extra.numpy import arrays
  from sklearn.linear_model import LogisticRegression
  from sklearn.multiclass import OneVsRestClassifier
  from cleanlab import multilabel_classification
  from cleanlab.internal import multilabel_scorer
  from cleanlab.internal.multilabel_utils import get_onehot_num_classes, onehot2int, stack_complement
  from cleanlab.multilabel_classification import filter
  from cleanlab.multilabel_classification.dataset import common_multilabel_issues, multilabel_health_summary, overall_multilabel_health_score, rank_classes_by_multilabel_quality
  from cleanlab.multilabel_classification.rank import get_label_quality_scores_per_class
label_desc: Use image node_id 4 for calling the TestAggregator obj's underlying member method code with example usage: obj.test_invalid_method() without return types