code: def __init__(self, opt, shared=None):
      # initialize fields
      self.opt = copy.deepcopy(opt)
      self.minfreq = opt.get(
          "dict_minfreq", DictionaryAgent.default_minfreq
      )
      self.null_token = "__PAD__"
      self.end_token = "__SOC__"
      self.unk_token = "__UNK__"
      self.start_token = "__SOC__"
      self.tokenizer = opt.get("dict_tokenizer", "whitespace")
      self.lower = opt.get("dict_lower", DictionaryAgent.default_lower)
      self.maxtokens = opt.get(
          "dict_maxtokens", DictionaryAgent.default_maxtokens
      )
      self.textfields = opt.get(
          "dict_textfields", DictionaryAgent.default_textfields
      ).split(",")
  
      if shared:
          self.freq = shared.get("freq", {})
          self.tok2ind = shared.get("tok2ind", {})
          self.ind2tok = shared.get("ind2tok", {})
      else:
          self.freq = defaultdict(int)
          self.tok2ind = {}
          self.ind2tok = {}
  
          if opt.get("dict_file") and os.path.isfile(opt["dict_file"]):
              # load pre-existing dictionary
              self.load(opt["dict_file"])
          elif opt.get("dict_initpath"):
              # load seed dictionary
              opt["dict_initpath"] = modelzoo_path(
                  opt.get("datapath"), opt["dict_initpath"]
              )
              self.load(opt["dict_initpath"])
  
          self.add_token(self.null_token)
          self.add_token(self.start_token)
          self.add_token(self.end_token)
          self.add_token(self.unk_token)
  
      if not shared:
          if opt.get("dict_file"):
              self.save_path = opt["dict_file"]
  
      # cache unk token for later
      self._unk_token_idx = self.tok2ind.get(self.unk_token)
  
file_path: ParlAI/projects/wizard_of_wikipedia/wizard_transformer_ranker/wizard_dict.py
imports: from parlai.core.build_data import modelzoo_path
  from parlai.core.dict import DictionaryAgent
  from collections import defaultdict
  import copy
  import os
  import re
label_desc: Use image node_id 1 to create a new WizardDictAgent object from inherited base classes: DictionaryAgent with example: obj = WizardDictAgent(opt, shared)