code: def test_new_tokenizer_registration(self):
      try:
          AutoConfig.register("custom", CustomConfig)
  
          AutoTokenizer.register(
              CustomConfig, slow_tokenizer_class=CustomTokenizer
          )
          # Trying to register something existing in the Transformers library will raise an error
          with self.assertRaises(ValueError):
              AutoTokenizer.register(
                  BertConfig, slow_tokenizer_class=BertTokenizer
              )
  
          tokenizer = CustomTokenizer.from_pretrained(
              SMALL_MODEL_IDENTIFIER
          )
          with tempfile.TemporaryDirectory() as tmp_dir:
              tokenizer.save_pretrained(tmp_dir)
  
              new_tokenizer = AutoTokenizer.from_pretrained(tmp_dir)
              self.assertIsInstance(new_tokenizer, CustomTokenizer)
  
      finally:
          if "custom" in CONFIG_MAPPING._extra_content:
              del CONFIG_MAPPING._extra_content["custom"]
          if CustomConfig in TOKENIZER_MAPPING._extra_content:
              del TOKENIZER_MAPPING._extra_content[CustomConfig]
  
imports: import os
  import shutil
  import sys
  import tempfile
  import unittest
  from pathlib import Path
  import pytest
  import transformers
  from transformers import BERT_PRETRAINED_CONFIG_ARCHIVE_MAP, GPT2_PRETRAINED_CONFIG_ARCHIVE_MAP, AutoTokenizer, BertConfig, BertTokenizer, BertTokenizerFast, CTRLTokenizer, GPT2Tokenizer, GPT2TokenizerFast, PreTrainedTokenizerFast, RobertaTokenizer, RobertaTokenizerFast, is_tokenizers_available
  from transformers.models.auto.configuration_auto import CONFIG_MAPPING, AutoConfig
  from transformers.models.auto.tokenization_auto import TOKENIZER_MAPPING, get_tokenizer_config, tokenizer_class_from_name
  from transformers.models.roberta.configuration_roberta import RobertaConfig
  from transformers.testing_utils import DUMMY_DIFF_TOKENIZER_IDENTIFIER, DUMMY_UNKNOWN_IDENTIFIER, SMALL_MODEL_IDENTIFIER, RequestCounter, require_tokenizers, slow
  from test_module.custom_configuration import CustomConfig
  from test_module.custom_tokenization import CustomTokenizer
label_desc: Use image node_id 18 for calling the AutoTokenizerTest obj's underlying member method code with example usage: obj.test_new_tokenizer_registration() without return types