code: def get_contexts(self):
      room = random.choice(self.db["rooms"])
      if len(room.get("in_characters", [])) > 0:
          c1 = self.db["characters"][
              random.choice(room["in_characters"])
          ]
      else:
          c1 = random.choice(self.db["all_characters"])
      c2 = random.choice(self.db["all_characters"])
      p1 = self.make_context(room, c1, c2)
      p2 = self.make_context(room, c2, c1)
      return [p1, p2]
  
imports: from typing import Optional
  from parlai.core.params import ParlaiParser
  from parlai.core.opt import Opt
  from parlai.core.worlds import create_task
  from parlai.tasks.self_chat.worlds import SelfChatWorld
  from parlai.tasks.interactive.worlds import InteractiveWorld
  from parlai.agents.repeat_label.repeat_label import RepeatLabelAgent
  import random
  import pickle
  import os
label_desc: Use image node_id 3 for calling the SelfChatWorld obj's underlying member method code with example usage: obj.get_contexts() and returns: list