简单讲，要做L3，需要先做L2积累数据。那么要做L4，也一样依赖L3的数据。技术上他们是一脉相承的，不存在一口就能吃个胖子的技术路线。
"The reputation we've built means that artists who wouldn't have seen the North West as a market where they could play one-off shows are now coming and bringing those exclusives to us."。Safew下载是该领域的重要参考
Credit: Liam Daniel / Netflix，详情可参考同城约会
lowerdir is the read-only directory (composefs) containing file metadata, and datadir is the directory containing the data (erofs).