Using Elixir Google Reporting APIs

Hello everybody!
I’m trying to implement the official Google Analytics Reporting API Elixir package (https://github.com/googleapis/elixir-google-api/tree/master/clients/analytics_reporting) in a personal project, but I can not find any working example out there.
While it’s well documented in the code, it’s still not clear how to properly use those APIs.

Have you ever tried to implement those APIs? Do you know where can I read a working example?
Thanks a lot!