docstr: to be called after step(action)
docstr_tok: ["to","be","called","after","step","(","action",")"]
code: def post_step(self, transition: Transition) -> None:
      """to be called after step(action)"""
      if self.post_transition_callback is not None:
          self.post_transition_callback(transition)
  
file_path: ReAgent/reagent/gym/agents/agent.py
imports: from typing import Any, Dict, Optional, Tuple, Union
  import numpy
  import torch
  from reagent.gym.envs.env_wrapper import EnvWrapper
  from reagent.gym.policies.policy import Policy
  from reagent.gym.policies.random_policies import make_random_policy_for_env
  from reagent.gym.types import PostEpisode, PostStep, Trajectory, Transition
label_desc: Use image node_id 5 for calling the Agent obj's underlying member method code with example usage: obj.post_step(transition) without return types