class_docstr: Flickr default teacher that expects open-ended descriptions of images.
code: def __init__(self, opt, shared=None):
      super().__init__(opt, shared)
      self.image_mode = opt.get("image_mode", "no_image_model")
      self.use_intro = opt.get("use_intro", False)
      self.num_cands = opt.get("num_cands", -1)
      data_path, self.image_path = _path(opt)
  
      if shared:
          # another instance was set up already, just reference its data
          self.data = shared["data"]
          self.image_loader = shared["image_loader"]
          if "cands" in shared:
              self.cands = shared["cands"]
      else:
          # need to set up data from scratch
          self._setup_data(data_path)
          self.image_loader = ImageLoader(opt)
  
      self.reset()
  
imports: from typing import Optional
  from parlai.core.params import ParlaiParser
  from parlai.core.opt import Opt
  from parlai.core.teachers import FixedDialogTeacher
  from parlai.core.image_featurizers import ImageLoader
  from parlai.utils.io import PathManager
  from .build import build
  import os
  import json
  import random
label_desc: Use image node_id 1 to create a new DefaultTeacher object from inherited base classes: FixedDialogTeacher with example: obj = DefaultTeacher(opt, shared)