code: def test_model_loading(self):
      for (
          pretrained_model_name
      ) in BERTTokenizer.available_checkpoints():
          tokenizer = BERTTokenizer(
              pretrained_model_name=pretrained_model_name
          )
          _ = tokenizer.map_text_to_token("UNwant\u00E9d,running")
  
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 3 for calling the BERTTokenizerTest obj's underlying member method code with example usage: obj.test_model_loading() without return types