code: def get_tokenizer(self, **kwargs):
      kwargs.update(self.special_tokens_map)
      return self.tokenizer_class.from_pretrained(
          self.tmpdirname, **kwargs
      )
  
imports: import itertools
  import json
  import os
  import unittest
  from transformers import AddedToken, LongformerTokenizer, LongformerTokenizerFast
  from transformers.models.longformer.tokenization_longformer import VOCAB_FILES_NAMES
  from transformers.testing_utils import require_tokenizers, slow
  from ...test_tokenization_common import TokenizerTesterMixin
label_desc: Use image node_id 2 for calling the LongformerTokenizationTest obj's underlying member method code with example usage: obj.get_tokenizer() and returns: self