code: def num_special_tokens_to_add(self):
      if not hasattr(self, "_num_specials"):
          self._num_specials = (
              self.tokenizer.num_special_tokens_to_add()
          )
      return self._num_specials
  
file_path: OpenPrompt/tutorial/7_ernie_paddlepaddle/TokenizerWrapper.py
imports: from utils import TokenizerWrapper
  from collections import defaultdict
label_desc: Use image node_id 3 for calling the ErnieMLMTokenizerWrapper obj's underlying member method code with example usage: obj.num_special_tokens_to_add() and returns: self