class_docstr: Generates a controllable_gen version of a ParlAI task, i.e., for tasks with multi-
  turn dialogues (episodes), this will generate a task with single example episodes,
  in which we append to the context a special classification token.
class_docstr_tok: ["Generates","a","controllable_gen","version","of","a","ParlAI","task",",","i.e.",",","for","tasks","with","multi-","turn","dialogues","(","episodes",")",",","this","will","generate","a","task","with","single","example","episodes",",","in","which","we","append","to","the","context","a","special","classification","token","."]
code: def num_episodes(self) -> int:
      return len(self.data)
  
imports: from parlai.core.params import ParlaiParser
  from parlai.core.message import Message
  from parlai.core.opt import Opt
  from parlai.core.teachers import FixedDialogTeacher
  from parlai.utils.io import PathManager
  import parlai.utils.logging
  from parlai.utils.typing import TShared
  from parlai.tasks.genderation_bias.build import build
  from parlai.tasks.genderation_bias.utils import flatten_and_classify, get_original_task_module
  from copy import deepcopy
  import datetime
  import glob
  import json
  import os
  from tqdm import tqdm
  from typing import List, Optional, Tuple
label_desc: Use image node_id 3 for calling the ControllableTaskTeacher obj's underlying member method code with example usage: obj.num_episodes() and returns: len