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 reset(self):
      super().reset()  # call parent reset so other fields can be set up
      self.example = None  # set up caching fields
      self.imageEpochDone = False
  
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 3 for calling the DefaultTeacher obj's underlying member method code with example usage: obj.reset() without return types