code: def _get_reference(self):
          
          super()._get_reference()
          self.cube_body_id = self.sim.model.body_name2id("pot")
          self.handle_1_site_id = self.sim.model.site_name2id("pot_handle_1")
          self.handle_2_site_id = self.sim.model.site_name2id("pot_handle_2")
          self.table_top_id = self.sim.model.site_name2id("table_top")
          self.pot_center_id = self.sim.model.site_name2id("pot_center")
docs: Sets up references to important components. A reference is typically an
          index or a list of indices that point to the corresponding elements
          in a flattened array, which is how MuJoCo stores physical simulation data.