public class DemoBlock extends BlockWithEntity {
 
    [...]
    
    @Override
    public void appendTooltip(ItemStack stack, Item.TooltipContext context, List<Text> tooltip, TooltipType options) {
        final Integer i = stack.get(TutorialDataComponentTypes.NUMBER);
        if (i == null) return;

        tooltip.add(Text.literal("数字：" + i));
    }
}