class_docstr: Predict the gender of character given the dialogue utterance.
class_docstr_tok: ["Predict","the","gender","of","character","given","the","dialogue","utterance","."]
code: def num_examples(self):
      return len(self.data)
  
imports: from typing import Optional
  from parlai.core.params import ParlaiParser
  from parlai.core.opt import Opt
  from parlai.core.message import Message
  from parlai.core.teachers import FixedDialogTeacher
  from parlai.tasks.convai2.agents import BothTeacher
  from parlai.tasks.md_gender.build import build
  from parlai.utils.misc import warn_once
  import parlai.tasks.md_gender.utils
  from copy import deepcopy
  import json
  import random
  import os
label_desc: Use image node_id 5 for calling the Convai2Teacher obj's underlying member method code with example usage: obj.num_examples() and returns: len