code: def close(self):
      if self.viewer:
          self.viewer.close()
  
file_path: PARL/examples/tutorials/parl2_dygraph/lesson5/ddpg/env.py
imports: import math
  import gym
  from gym import spaces, logger
  from gym.utils import seeding
  import numpy
label_desc: Use image node_id 7 for calling the ContinuousCartPoleEnv obj's underlying member method code with example usage: obj.close() without return types