code: def test_class_variables_for_namespace_warnings_work_correctly(self):
      # pylint: disable=protected-access
      assert "text" not in MultiLabelField._already_warned_namespaces
      with self.assertLogs(
          logger="allennlp.data.fields.multilabel_field",
          level="WARNING",
      ):
          _ = MultiLabelField(["test"], label_namespace="text")
  
      # We've warned once, so we should have set the class variable to False.
      assert "text" in MultiLabelField._already_warned_namespaces
      with pytest.raises(AssertionError):
          with self.assertLogs(
              logger="allennlp.data.fields.multilabel_field",
              level="WARNING",
          ):
              _ = MultiLabelField(["test2"], label_namespace="text")
  
      # ... but a new namespace should still log a warning.
      assert "text2" not in MultiLabelField._already_warned_namespaces
      with self.assertLogs(
          logger="allennlp.data.fields.multilabel_field",
          level="WARNING",
      ):
          _ = MultiLabelField(["test"], label_namespace="text2")
  
imports: from __future__ import with_statement
  from __future__ import absolute_import
  from __future__ import print_function
  import numpy
  import pytest
  from allennlp.common.checks import ConfigurationError
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.data.fields import MultiLabelField
  from allennlp.data.vocabulary import Vocabulary
label_desc: Use image node_id 9 for calling the TestMultiLabelField obj's underlying member method code with example usage: obj.test_class_variables_for_namespace_warnings_work_correctly() without return types