3-continuous-actor-critic에서 cartpolecontinuous 가 등록되지 않습니다.

[parkhyunjun77]

Error Traceback (most recent call last)
in
96 entry_point='env:ContinuousCartPoleEnv',
97 max_episode_steps=500,
---> 98 reward_threshold=475.0)
99
100 env = gym.make('CartPoleContinuous-v0')

c:\users\ .\gym\gym\envs\registration.py in register(id, **kwargs)
140
141 def register(id, **kwargs):
--> 142 return registry.register(id, **kwargs)
143
144 def make(id, **kwargs):

c:\users\ .\gym\gym\envs\registration.py in register(self, id, **kwargs)
133 def register(self, id, **kwargs):
134 if id in self.env_specs:
--> 135 raise error.Error('Cannot re-register id: {}'.format(id))
136 self.env_specs[id] = EnvSpec(id, **kwargs)
137

Error: Cannot re-register id: CartPoleContinuous-v0

어떤 문제일까요..?