class_docstr: A reward shaping wraper
class_docstr_tok: ["A","reward","shaping","wraper"]
code: def reward_shaping(self, state_desc, r2_reward, done, action):
      info = {"shaping_reward": r2_reward}
      return info
  
imports: import abc
  import copy
  import gym
  import math
  import numpy
  from collections import OrderedDict
  from osim.env import L2M2019Env
  from parl.utils import logger
label_desc: Use image node_id 2 for calling the ForwardReward obj's underlying member method code with example usage: obj.reward_shaping(state_desc, r2_reward, done, action) and returns: info