text: import numpy as np
  from jiminy.gym import utils
  from jiminy.gym.envs.mujoco import mujoco_env
  
  import mujoco_py
  
  class PusherEnv(mujoco_env.MujocoEnv, utils.EzPickle):
      def __init__(self):
          utils.EzPickle.__init__(self)
          mujoco_env.MujocoEnv.__init__(self, 'pusher.xml', 5)
  
      def _step(self, a):
          vec_1 = self.get_body_com("object") - self.get_body_com("tips_arm")
          vec_2 = self.get_body_com("object") - self.get_body_com("goal")
  
          reward_near = - np.linalg.norm(vec_1)
          reward_dist = - np.linalg.norm(vec_2)
          reward_ctrl = - np.square(a).sum()
          reward = reward_dist + 0.1 * reward_ctrl + 0.5 * reward_near
  
          self.do_simulation(a, self.frame_skip)
          ob = self._get_obs()
          done = False
          return ob, reward, done, dict(reward_dist=reward_dist,
                  reward_ctrl=reward_ctrl)
  
      def viewer_setup(self):
          self.viewer.cam.trackbodyid = -1
          self.viewer.cam.distance = 4.0
  
      def reset_model(self):
          qpos = self.init_qpos
  
          self.goal_pos = np.asarray([0, 0])
          while True:
              self.cylinder_pos = np.concatenate([
                      self.np_random.uniform(low=-0.3, high=0, size=1),
                      self.np_random.uniform(low=-0.2, high=0.2, size=1)])
              if np.linalg.norm(self.cylinder_pos - self.goal_pos) > 0.17:
                  break
  
          qpos[-4:-2] = self.cylinder_pos
          qpos[-2:] = self.goal_pos
          qvel = self.init_qvel + self.np_random.uniform(low=-0.005,
                  high=0.005, size=self.model.nv)
          qvel[-4:] = 0
          self.set_state(qpos, qvel)
          return self._get_obs()
  
      def _get_obs(self):
          return np.concatenate([
              self.sim.data.qpos.flat[:7],
              self.sim.data.qvel.flat[:7],
              self.get_body_com("tips_arm"),
              self.get_body_com("object"),
              self.get_body_com("goal"),
          ])
  