class_docstr: ParlAI agent exported to TorchScript with JIT compilation and then loaded from disk.
  
  Metrics and batch act are currently unsupported, and CUDA is unsupported because
  TorchScripting is currently CPU-only.
code: def observe(self, observation: Message) -> Message:
      # TODO: support self._validate_observe_invariants() method of TorchAgent
  
      self.history.append(observation["text"])
  
      return super().observe(observation)
  
file_path: ParlAI/parlai/torchscript/agents.py
imports: from typing import List
  import torch
  from parlai.core.agents import Agent
  from parlai.core.message import Message
  from parlai.core.opt import Opt
  from parlai.utils.io import PathManager
label_desc: Use image node_id 3 for calling the TorchScriptAgent obj's underlying member method code with example usage: obj.observe(observation) and returns: super