code: def test_known_configs(self):
      configs = os.listdir(self.PROJECT_ROOT / "training_config")
  
      # Our configs use environment variable substitution, and the _jsonnet parser
      # will fail if we don't pass it correct environment variables.
      forced_variables = [
          # constituency parser
          "PTB_TRAIN_PATH",
          "PTB_DEV_PATH",
          "PTB_TEST_PATH",
          # dependency parser
          "PTB_DEPENDENCIES_TRAIN",
          "PTB_DEPENDENCIES_VAL",
          # multilingual dependency parser
          "TRAIN_PATHNAME",
          "DEV_PATHNAME",
          "TEST_PATHNAME",
          # srl_elmo_5.5B
          "SRL_TRAIN_DATA_PATH",
          "SRL_VALIDATION_DATA_PATH",
          # coref
          "COREF_TRAIN_DATA_PATH",
          "COREF_DEV_DATA_PATH",
          "COREF_TEST_DATA_PATH",
          # ner
          "NER_TRAIN_DATA_PATH",
          "NER_TEST_A_PATH",
          "NER_TEST_B_PATH",
          # bidirectional lm
          "BIDIRECTIONAL_LM_TRAIN_PATH",
          "BIDIRECTIONAL_LM_VOCAB_PATH",
          "BIDIRECTIONAL_LM_ARCHIVE_PATH",
      ]
  
      for var in forced_variables:
          os.environ[var] = os.environ.get(var) or str(self.TEST_DIR)
  
      for config in configs:
          try:
              Params.from_file(
                  self.PROJECT_ROOT / "training_config" / config
              )
          except Exception as e:
              raise AssertionError(
                  f"unable to load params for {config}, because {e}"
              )
  
      for var in forced_variables:
          if os.environ[var] == str(self.TEST_DIR):
              del os.environ[var]
  
imports: import json
  import os
  import re
  from collections import OrderedDict
  import pytest
  from allennlp.common.checks import ConfigurationError
  from allennlp.common.params import infer_and_cast, Params, remove_keys_from_params, with_overrides
  from allennlp.common.testing import AllenNlpTestCase
label_desc: Use image node_id 11 for calling the TestParams obj's underlying member method code with example usage: obj.test_known_configs() without return types