code: def setup_method(self):
      super().setup_method()
      self.word_tokenizer = LettersDigitsTokenizer()
  
file_path: allennlp/tests/data/tokenizers/letters_digits_tokenizer_test.py
imports: from allennlp.common.testing import AllenNlpTestCase
  from allennlp.data.tokenizers import Token, LettersDigitsTokenizer
label_desc: Use image node_id 1 for calling the TestLettersDigitsTokenizer obj's underlying member method code with example usage: obj.setup_method() without return types