code: def test_class_variables_for_namespace_warnings_work_correctly(
      self, caplog
  ):
      with caplog.at_level(
          logging.WARNING, logger="allennlp.data.fields.label_field"
      ):
          assert "text" not in LabelField._already_warned_namespaces
          _ = LabelField("test", label_namespace="text")
          assert caplog.records
  
          # We've warned once, so we should have set the class variable to False.
          assert "text" in LabelField._already_warned_namespaces
          caplog.clear()
          _ = LabelField("test2", label_namespace="text")
          assert not caplog.records
  
          # ... but a new namespace should still log a warning.
          assert "text2" not in LabelField._already_warned_namespaces
          caplog.clear()
          _ = LabelField("test", label_namespace="text2")
          assert caplog.records
  
file_path: allennlp/tests/data/fields/label_field_test.py
imports: import logging
  import pytest
  from allennlp.common.checks import ConfigurationError
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.data.fields import LabelField
  from allennlp.data import Vocabulary
label_desc: Use image node_id 6 for calling the TestLabelField obj's underlying member method code with example usage: obj.test_class_variables_for_namespace_warnings_work_correctly(caplog) without return types