code: def _parse_knowledge(self, obs):
      if "knowledge_parsed" in obs:
          # make a copy of the list to prevent the future padding step from
          # being destructive
          return list(obs["knowledge_parsed"])
  
      if "checked_sentence" not in obs:
          # interactive time. we're totally on our own
          obs_know = [
              k.strip()
              for k in obs.get("knowledge", "no_passages_used").split(
                  "\n"
              )
          ]
          obs_know = [k for k in obs_know if k]
          obs["knowledge_parsed"] = obs_know
          return obs["knowledge_parsed"]
  
      checked_sentence = "{} {} {}".format(
          obs["title"], TOKEN_KNOWLEDGE, obs["checked_sentence"]
      )
      # grab all the nonempty knowledge
      obs_know = [
          k.strip()
          for k in obs.get("knowledge", "no_passages_used").split("\n")
      ]
      obs_know = [k for k in obs_know if k]
  
      # we want the correct knowledge to always be in index 0
      try:
          i = obs_know.index(checked_sentence)
      except ValueError:
          # uh oh, couldn't find the sentence in the knowledge. This happens for
          # one or two examples in the training set. We can just artificially
          # put it back in
          i = 0
          obs_know[0] = checked_sentence
      obs_know[0], obs_know[i] = obs_know[i], obs_know[0]
  
      obs["knowledge_parsed"] = obs_know
      obs["checked_sentence_parsed"] = checked_sentence
      return obs["knowledge_parsed"]
  
imports: from typing import Optional
  from parlai.core.params import ParlaiParser
  from parlai.core.opt import Opt
  from itertools import chain
  from functools import lru_cache
  import torch
  import numpy
  from parlai.utils.torch import padded_tensor
  from parlai.utils.misc import round_sigfigs
  from parlai.agents.transformer.transformer import TransformerGeneratorAgent
  from .modules import EndToEndModel
  from parlai.tasks.wizard_of_wikipedia.agents import TOKEN_KNOWLEDGE
label_desc: Use image node_id 5 for calling the EndToEndAgent obj's underlying member method code with example usage: obj._parse_knowledge(obs) and returns: obs, list, obs