code: def test_class_variables_for_namespace_warnings_work_correctly(
      self, caplog
  ):
      with caplog.at_level(
          logging.WARNING,
          logger="allennlp.data.fields.multilabel_field",
      ):
          assert (
              "text" not in MultiLabelField._already_warned_namespaces
          )
          _ = MultiLabelField(["test"], label_namespace="text")
          assert caplog.records
  
          # We've warned once, so we should have set the class variable to False.
          assert "text" in MultiLabelField._already_warned_namespaces
          caplog.clear()
          _ = MultiLabelField(["test2"], label_namespace="text")
          assert not caplog.records
  
          # ... but a new namespace should still log a warning.
          assert (
              "text2" not in MultiLabelField._already_warned_namespaces
          )
          caplog.clear()
          _ = MultiLabelField(["test"], label_namespace="text2")
          assert caplog
  
imports: import logging
  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(caplog) without return types