code: def decrement_display_ref_count(self, amount: int=1):
          
          assert not self._closed
          self.__display_ref_count -= amount
          if self.__display_ref_count == 0:
              self.__is_master = False
          if self.__data_item:
              for _ in range(amount):
                  self.__data_item.decrement_data_ref_count()
docs: Decrement display reference count to indicate this library item is no longer displayed.