code: def reset(self):
      ob = self.env.reset()
      assert ob.shape[2] > self.channel
      for _ in range(self.k):
          self.frames.append(ob)
      return self._get_ob()
  
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 2 for calling the PartialFrameStack obj's underlying member method code with example usage: obj.reset() and returns: self