code: def merge_visual(self, mujoco_objects):
          
          self.visual_obj_mjcf = []
          for obj_name, obj_mjcf in mujoco_objects.items():
              self.merge_asset(obj_mjcf)
              # Load object
              obj = obj_mjcf.get_visual(name=obj_name, site=False)
              self.visual_obj_mjcf.append(obj)
              self.worldbody.append(obj)
docs: Adds visual objects to the MJCF model.