code: def _wildcards(self, response, match):
      pos = response.find("%")
      while pos >= 0:
          num = int(response[pos + 1 : pos + 2])
          response = (
              response[:pos]
              + self._substitute(match.group(num))
              + response[pos + 2 :]
          )
          pos = response.find("%")
      return response
  
file_path: nltk/nltk/chat/util.py
imports: import random
  import re
label_desc: Use image node_id 4 for calling the Chat obj's underlying member method code with example usage: obj._wildcards(response, match) and returns: response