docstr: Stub observe method.
docstr_tok: ["Stub","observe","method","."]
code: def observe(self, obs):
      """
      Stub observe method.
      """
      self.observation = obs
  
imports: from typing import Optional
  from parlai.core.params import ParlaiParser
  from parlai.core.opt import Opt
  import json
  import re
  from parlai.core.agents import Agent
  from parlai.core.dict import DictionaryAgent
  from itertools import islice
  from parlai.utils.io import PathManager
label_desc: Use image node_id 5 for calling the UnigramAgent obj's underlying member method code with example usage: obj.observe(obs) without return types