code: def test_create_vocab(self):
      data_file_path = self.create_test_data()
      tokenizer = RegExTokenizer(regex=DEFAULT_REGEX)
      tokenizer.build_vocab_from_csv(data_csv_file=data_file_path)
  
      assert len(tokenizer.vocab) == 18
  
file_path: NeMo/tests/collections/nlp/test_regex_tokenizer.py
imports: import tempfile
  import pytest
  from nemo.collections.common.tokenizers.regex_tokenizer import RegExTokenizer
label_desc: Use image node_id 2 for calling the TestRegexTokenizer obj's underlying member method code with example usage: obj.test_create_vocab() without return types