class_docstr: Trait for flatten persona into one line.
class_docstr_tok: ["Trait","for","flatten","persona","into","one","line","."]
code: def __init__(self, opt, shared=None):
      self.is_convai2_session_level = opt.get(
          "is_convai2_session_level", False
      )
      super().__init__(opt, shared)
  
imports: from parlai.core.teachers import DialogTeacher
  from parlai.utils.io import PathManager
  from parlai.core.opt import Opt
  from parlai.utils.strings import normalize_reply
  from parlai.core.teachers import MultiTaskTeacher
  from .build import build
  import os
  import json
  from typing import Optional
  from parlai.core.params import ParlaiParser
  import copy
  import random
  import math
  from parlai.utils.logging import logger
  from parlai.core.message import Message
  import parlai.scripts.display_data
  from parlai.tasks.convai2.agents import NormalizedTeacherTrait, SelfOriginalTeacher
  from parlai.tasks.blended_skill_talk.agents import ContextGenerator
  from parlai.tasks.msc.constants import INITIAL_DATA_TO_COMPLETE, MODEL_OPT, UI_OPT, COMMON_CONFIG
  import parlai.tasks.msc.mutators
label_desc: Use image node_id 2 to create a new Session1NormalizedTrait object from inherited base classes: NormalizedTeacherTrait with example: obj = Session1NormalizedTrait(opt, shared)