text: import gym
  import numpy as np
  
  from garage.envs.mujoco import HalfCheetahEnv
  from garage.envs.mujoco.hill import HillEnv
  from garage.envs.mujoco.hill import terrain
  from garage.misc.overrides import overrides
  
  
  class HalfCheetahHillEnv(HillEnv):
  
      MODEL_CLASS = HalfCheetahEnv
  
      @overrides
      def _mod_hfield(self, hfield):
          # clear a flat patch for the robot to start off from
          return terrain.clear_patch(
              hfield,
              gym.spaces.Box(
                  np.array([-3.0, -1.5]),
                  np.array([0.0, -0.5]),
                  dtype=np.float32))
  