code: def test_add_tokens(self):
      tokenizer = BERTTokenizer.load(self.vocab_file)
  
      vocab_size = tokenizer.vocab_size
      all_size = len(tokenizer)
  
      self.assertNotEqual(vocab_size, 0)
      self.assertEqual(vocab_size, all_size)
  
      new_toks = ["aaaaabbbbbb", "cccccccccdddddddd"]
      added_toks = tokenizer.add_tokens(new_toks)
      vocab_size_2 = tokenizer.vocab_size
      all_size_2 = len(tokenizer)
  
      self.assertNotEqual(vocab_size_2, 0)
      self.assertEqual(vocab_size, vocab_size_2)
      self.assertEqual(added_toks, len(new_toks))
      self.assertEqual(all_size_2, all_size + len(new_toks))
  
      tokens = tokenizer.map_text_to_id(
          "aaaaabbbbbb low cccccccccdddddddd l"
      )
      self.assertGreaterEqual(len(tokens), 4)
      self.assertGreater(tokens[0], tokenizer.vocab_size - 1)
      self.assertGreater(tokens[-2], tokenizer.vocab_size - 1)
  
      new_toks_2 = {
          "eos_token": ">>>>|||<||<<|<<",
          "pad_token": "<<<<<|||>|>>>>|>",
      }
      added_toks_2 = tokenizer.add_special_tokens(new_toks_2)
      vocab_size_3 = tokenizer.vocab_size
      all_size_3 = len(tokenizer)
  
      self.assertNotEqual(vocab_size_3, 0)
      self.assertEqual(vocab_size, vocab_size_3)
      self.assertEqual(added_toks_2, len(new_toks_2))
      self.assertEqual(all_size_3, all_size_2 + len(new_toks_2))
  
      tokens = tokenizer.map_text_to_id(
          ">>>>|||<||<<|<< aaaaabbbbbb low cccccccccdddddddd "
          "<<<<<|||>|>>>>|> l"
      )
  
      self.assertGreaterEqual(len(tokens), 6)
      self.assertGreater(tokens[0], tokenizer.vocab_size - 1)
      self.assertGreater(tokens[0], tokens[1])
      self.assertGreater(tokens[-2], tokenizer.vocab_size - 1)
      self.assertGreater(tokens[-2], tokens[-3])
      self.assertEqual(
          tokens[0], tokenizer.map_token_to_id(tokenizer.eos_token)
      )
      self.assertEqual(
          tokens[-2], tokenizer.map_token_to_id(tokenizer.pad_token)
      )
  
file_path: texar/tests/data/tokenizers/bert_tokenizer_test.py
imports: import os
  import pickle
  import tempfile
  import tensorflow
  from texar.tf.data.tokenizers.bert_tokenizer import BERTTokenizer
  from texar.tf.utils.test import pretrained_test
label_desc: Use image node_id 9 for calling the BERTTokenizerTest obj's underlying member method code with example usage: obj.test_add_tokens() without return types