code: def setUp(self):
      super().setUp()
  
      # We have a SentencePiece fixture for testing
      tokenizer = PegasusTokenizer(
          SAMPLE_VOCAB,
          offset=0,
          mask_token_sent=None,
          mask_token="[MASK]",
      )
      tokenizer.save_pretrained(self.tmpdirname)
  
imports: import unittest
  from transformers import PegasusTokenizer, PegasusTokenizerFast
  from transformers.testing_utils import get_tests_dir, require_sentencepiece, require_tokenizers, require_torch, slow
  from transformers.utils import cached_property
  from ...test_tokenization_common import TokenizerTesterMixin
label_desc: Use image node_id 1 for calling the BigBirdPegasusTokenizationTest obj's underlying member method code with example usage: obj.setUp() without return types