版本：
文件：
- https://cdn.bootcdn.net/ajax/libs/labjs/2.0.3/LAB-debug.min.js
- https://cdn.bootcdn.net/ajax/libs/labjs/2.0.3/LAB.min.js
LABjs (Loading And Blocking JavaScript) is an open-source (MIT license) project supported by Getify Solutions. The core purpose of LABjs is to be an all-purpose, on-demand JavaScript loader, capable of loading any JavaScript resource, from any location, into any page, at any time. Loading your scripts with LABjs reduces resource blocking during page-load, which is an easy and effective way to optimize your site's performance.