def __init__(self, env, k, channel=<NUM_LIT:1>):
gym.Wrapper.__init__(self, env)<EOL>shp = env.observation_space.shape<EOL>self.channel = channel<EOL>self.observation_space = gym.spaces.Box(low=<NUM_LIT:0>, high=<NUM_LIT:255>,<EOL>shape=(shp[<NUM_LIT:0>], shp[<NUM_LIT:1>], shp[<NUM_LIT:2>] + k - <NUM_LIT:1>),<EOL>dtype=env.observation_space.dtype)<EOL>self.k = k<EOL>self.frames = deque([], maxlen=k)<EOL>shp = env.observation_space.shape<EOL>
Stack one channel (channel keyword) from previous frames