docstr: Very rudimentary way to calculate word overlap.
code: def __calculate_word_overlap(self, a, b):
      """
      Very rudimentary way to calculate word overlap.
      """
      score = 0
      tokens_a = a.split(" ")
      tokens_a = [ta for ta in tokens_a if len(ta) >= 5]
      for ta in tokens_a:
          if ta in b:
              score += 1
  
      tokens_b = b.split(" ")
      tokens_b = [tb for tb in tokens_b if len(tb) >= 5]
      for tb in tokens_b:
          if tb in a:
              score += 1
      return score
  
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 3 for calling the PersonaTopicifier obj's underlying member method code with example usage: obj.__calculate_word_overlap(a, b) and returns: score