code: def get_knowledge(self, obs):
      labels_kword = (
          "labels" if "train" in self.opt["datatype"] else "eval_labels"
      )
      if "wizardofwikipedia" in self.opt["task"].lower().replace(
          "_", ""
      ):
          return obs.get("checked_sentence", "")
      if "wizardofinternet" in self.opt["task"].lower().replace(
          "_", ""
      ):
          knowledge = obs.get("__selected-sentences__", "")
          if isinstance(knowledge, list):
              knowledge = "\n".join(knowledge)
          return knowledge
      elif (
          "nqopen" in self.opt["task"].lower()
          or "natural_questions" in self.opt["task"].lower()
      ):
          return obs.get(labels_kword, "")
      elif "LightTeacherPlus" in self.opt["task"]:
          if labels_kword not in obs or not obs[labels_kword]:
              return ""
          labels = obs[labels_kword]
          if not isinstance(labels, str):
              labels = labels[0]
          return knowledge_from_dialogue_response(labels)
      elif "SummaryQA" in self.opt["task"]:
          return obs.get(labels_kword, "")
      else:
          raise NotImplementedError(
              f'Task "{self.opt["task"]}" is not known.'
          )
  
imports: from copy import deepcopy
  from typing import Optional, List
  from types import MethodType
  from collections import defaultdict
  from nltk.tokenize import sent_tokenize
  from nltk.corpus import stopwords
  import random
  import spacy
  import torch
  from parlai.core.agents import create_agent, create_agent_from_shared
  from parlai.core.params import ParlaiParser
  from parlai.core.opt import Opt
  from parlai.core.message import Message
  from parlai.core.agents import Agent
  from parlai.core.metrics import F1Metric
  from parlai.agents.rag.args import setup_rag_args
  from parlai.agents.bart.bart import BartAgent
  from parlai.core.metrics import normalize_answer
  from parlai.tasks.wizard_of_wikipedia.agents import TOKEN_NOCHOSEN
  from parlai.tasks.wizard_of_wikipedia.agents import TOKEN_KNOWLEDGE, TOKEN_END_KNOWLEDGE
label_desc: Use image node_id 2 for calling the OracleKnowledgeAgent obj's underlying member method code with example usage: obj.get_knowledge(obs) and returns: obs, knowledge, obs, knowledge_from_dialogue_response, str, obs