code: def __init__(self, opt, shared=None):
      super(VqaDictionaryAgent, self).__init__(opt)
      self.id = "VqaDictionary"
      self.null_token = "__NULL__"
      self.unk_token = "__UNK__"
  
      if shared:
          self.freq = shared.get("freq", {})
          self.tok2ind = shared.get("tok2ind", {})
          self.ind2tok = shared.get("ind2tok", {})
          self.ans2ind = shared.get("ans2ind", {})
          self.ind2ans = shared.get("ind2ans", {})
      else:
          self.freq = defaultdict(int)
          self.ansfreq = defaultdict(int)
          self.ans2ques = defaultdict(list)
          self.tok2ind = {}
          self.ind2tok = {}
          self.ans2ind = {}
          self.ind2ans = {}
  
          if self.null_token:
              self.tok2ind[self.null_token] = 0
              self.ind2tok[0] = self.null_token
  
          if self.unk_token:
              # set special unknown word token
              index = len(self.tok2ind)
              self.tok2ind[self.unk_token] = index
              self.ind2tok[index] = self.unk_token
  
      if opt.get("dict_file") and PathManager.exists(opt["dict_file"]):
          # load pre-existing dictionary
          self.load(opt["dict_file"])
  
      if not shared:
          if self.null_token:
              # fix count for null token to one billion and two
              self.freq[self.null_token] = 1000000002
  
          if self.unk_token:
              # fix count for unknown token to one billion
              self.freq[self.unk_token] = 1000000000
  
          if opt.get("dict_file"):
              self.save_path = opt["dict_file"]
  
imports: from typing import Optional
  from parlai.core.params import ParlaiParser
  from parlai.core.opt import Opt
  import json
  import os
  import re
  import numpy
  from collections import Counter
  from parlai.core.agents import Agent
  from parlai.utils.io import PathManager
  from collections import defaultdict
  from parlai.core.teachers import FixedDialogTeacher
  from parlai.core.image_featurizers import ImageLoader
  from .build import build
  from parlai.tasks.coco_caption.build_2014 import buildImage
  from parlai.tasks.coco_caption.build_2015 import buildImage
label_desc: Use image node_id 2 to create a new VqaDictionaryAgent object from inherited base classes: Agent with example: obj = VqaDictionaryAgent(opt, shared)