class_docstr: Bring rewards to a reasonable scale for PPO.
  This is incredibly important and effects performance
  drastically.
class_docstr_tok: ["Bring","rewards","to","a","reasonable","scale","for","PPO",".","This","is","incredibly","important","and","effects","performance","drastically","."]
code: def __init__(self, env, scale=0.01):
      super(RewardScaler, self).__init__(env)
      self.scale = scale
  
imports: from collections import deque
  import cv2
  from .atari_wrappers import WarpFrame, ClipRewardEnv, FrameStack, ScaledFloatFrame
  from .wrappers import TimeLimit
  import numpy
  import gym
label_desc: Use image node_id 1 to create a new RewardScaler object from inherited base classes: gym with example: obj = RewardScaler(env, scale)