code: def token_list_len(tokenlist):
      
      ZeroWidthEscape = Token.ZeroWidthEscape
      return sum(len(item[1]) for item in tokenlist if item[0] != ZeroWidthEscape)
docs: Return the amount of characters in this token list.
  
      :param tokenlist: List of (token, text) or (token, text, mouse_handler)
                        tuples.