code: def _setup_personas_to_wow_topics(
      self,
  ) -> Tuple[Dict[str, List[str]], Dict[str, List[str]]]:
      persona_strings_to_topics = defaultdict(list)
      topics_to_persona_strings = defaultdict(list)
      with PathManager.open(self.topic_to_persona_path, "r") as f:
          for line in f:
              match = re.fullmatch(r"([^[]+): (\[.+\])\n", line)
              topic = match.group(1)
              persona_strings = eval(match.group(2))
              assert isinstance(persona_strings, list)
              topics_to_persona_strings[topic] = persona_strings
              for str_ in persona_strings:
                  persona_strings_to_topics[str_].append(topic)
  
      warn_once(
          f"FINISHED MAPPING personas to topics, got: {len(list(persona_strings_to_topics.keys()))} persona strings to map to topics."
      )
      return topics_to_persona_strings, persona_strings_to_topics
  
imports: import copy
  import os
  import random
  import re
  from collections import defaultdict
  from typing import List, Optional, Dict, Tuple
  from parlai.core.opt import Opt
  from parlai.core.teachers import ParlAIDialogTeacher, create_task_agent_from_taskname
  from parlai.tasks.convai2.agents import BothTeacher
  from parlai.tasks.empathetic_dialogues.agents import EmpatheticDialoguesTeacher
  from parlai.tasks.wizard_of_wikipedia.agents import WizardDialogKnowledgeTeacher
  from parlai.utils.misc import warn_once
  from parlai.utils.io import PathManager
  from .build import build
label_desc: Use image node_id 2 for calling the PersonaTopicifier obj's underlying member method code with example usage: obj._setup_personas_to_wow_topics() and returns: topics_to_persona_strings,  persona_strings_to_topics