code: def _reset_internal(self):
          
          super()._reset_internal()
          self.sim.data.qpos[self._ref_joint_pos_indexes] = self.mujoco_robot.init_qpos
  
          if self.has_gripper:
              self.sim.data.qpos[
                  self._ref_joint_gripper_actuator_indexes
              ] = self.gripper.init_qpos
docs: Sets initial pose of arm and grippers.