code: def test_vocab_size(self):
      self.assertEqual(self.get_tokenizer().vocab_size, 1_103)
  
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 7 for calling the PegasusTokenizationTest obj's underlying member method code with example usage: obj.test_vocab_size() without return types