class_docstr: Teacher for written two-person dialogues with labels being relevant/useful parts in
  the input sentence.
  
  The different datatypes of the labels within the data have also been encoded as
  `label_types`
class_docstr_tok: ["Teacher","for","written","two-person","dialogues","with","labels","being","relevant\/useful","parts","in","the","input","sentence",".","The","different","datatypes","of","the","labels","within","the","data","have","also","been","encoded","as","`","label_types","`"]
code: def num_episodes(self):
      return len(self.convos)
  
imports: from parlai.core.params import ParlaiParser
  import os
  import pandas
  from parlai.core.opt import Opt
  import parlai.core.tod.tod_core
  from typing import Optional
  from parlai.utils.data import DatatypeHelper
  from parlai.utils.io import PathManager
  import parlai.tasks.taskmaster.build
  import parlai.core.tod.tod_agents
  from parlai.core.teachers import FixedDialogTeacher
  from .None import tm_utils
  import json
label_desc: Use image node_id 4 for calling the SelfDialogueSegmentTeacher obj's underlying member method code with example usage: obj.num_episodes() and returns: len