This is an extension to most of Screeps' classes, an assortement of shorthands to make coding easier.
Copy all files from the Assets folder into your script's folder. Add require("X"); at the top of your main.js to automatically require everything.
The different extensions aren't dependant on each other, so you are able to cherry-pick the ones you want. Howver you'll need to remove the missing modules from X.js, or manually require each of the modules you picked.