code: def get_episode_rewards(self):
      return self._episode_rewards
  
imports: import time
  import numpy
  from collections import deque
  import gym
  from gym import spaces
  from parl.env.compat_wrappers import CompatWrapper, is_gym_version_ge, V_NPRANDOM_CHANGED
  import cv2
label_desc: Use image node_id 4 for calling the MonitorEnv obj's underlying member method code with example usage: obj.get_episode_rewards() and returns: self