This repository use your server to request google's server.
If your visitor use some blocker to block google's js,it can hide the google's js.
If your visitor can't connect google's server,it can help you.
Also,it can hide your tid of google analytics.
Load the main.js in all your pages.
Get your tid and set in analytics.php and put the analytics.php in the root directory of your website.
You can change the file name ans directory by yourself,and remember change in js code.