If you want to serve the file from your site, just download the relevant file, put it into a web accessible directory (such as www/js) and serve it as you would any local content.
Your user will still re-download the relevant files if they hit refresh, but it will be from your server rather than Google’s, which may or may not be beneficial.
It copies scripts from a protected location to a web accessible one. It’s intended to allow people to package up server and client scripts in one place rather than spread them across protected and web directories.