where is magento calling ga api

Hi all

Magento displays google analytics dashboard and other analytical data in their own admin section.

So to know how they are creating it i just downloaded "MAGENTO 2" and started inspecting their folders.

Are they creating it from the scratch ??

They must be using google analytics api BUT i am not able to find, In which file are they referencing the "google analytics api".

I mean i am not able to find, in which php file they are calling "google analytic api" ??

can anybody tell me ?

thanks
vineet