code: def _get_obs(self):
      return np.concatenate(
          [
              self.sim.data.qpos[:1],  # cart x pos
              np.sin(self.sim.data.qpos[1:]),  # link angles
              np.cos(self.sim.data.qpos[1:]),
              np.clip(self.sim.data.qvel, -10, 10),
              np.clip(self.sim.data.qfrc_constraint, -10, 10),
          ]
      ).ravel()
  
file_path: gym/gym/envs/mujoco/inverted_double_pendulum.py
imports: import numpy
  from gym import utils
  from gym.envs.mujoco import MuJocoPyEnv
  from gym.spaces import Box
label_desc: Use image node_id 3 for calling the InvertedDoublePendulumEnv obj's underlying member method code with example usage: obj._get_obs() and returns: np