code: def unescape(s):
      r"""
      Revert escaped characters back to their special version.
  
      For example, \\n => \n and \\t => \t
  
      :param s:
          string to unescape
      """
      return (
          s.replace("\\n", "\n")
          .replace("\\t", "\t")
          .replace("\\r", "\r")
      )
  
imports: from typing import Optional
  from parlai.core.params import ParlaiParser
  from parlai.core.opt import Opt
  from parlai.core.build_data import modelzoo_path
  from parlai.utils.bpe import bpe_factory, BPEHelper
  from .agents import Agent
  from .build_data import make_dir
  from collections import defaultdict
  import copy
  import numpy
  import os
  import json
  import re
  import parlai.utils.logging
  from parlai.utils.io import PathManager
  from typing import List
  import enum
label_desc: Use image node_id 2 for calling a global function with example usage: unescape(s) and returns: s