class_docstr: COCO default teacher that expects open-ended descriptions of images.
class_docstr_tok: ["COCO","default","teacher","that","expects","open-ended","descriptions","of","images","."]
code: def __init__(self, opt, shared=None, version="2017"):
      super().__init__(opt, shared)
      self.version = version
      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)
      self.include_rest_val = opt.get("include_rest_val", False)
      test_info_path, annotation_path, self.image_path = _path(
          opt, version
      )
      self.test_split = opt["test_split"]
  
      if shared:
          # another instance was set up already, just reference its data
          if "annotation" in shared:
              self.annotation = shared["annotation"]
          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(test_info_path, annotation_path, opt)
          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_2014 import build
  from .build_2014 import buildImage
  from .build_2017 import build
  from .build_2017 import buildImage
  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, version)