Topic: HaveRight session class

I want to know where the variable of session are set,
In the HaveRight function of session class
I search where $_SESSION["glpiactiveprofile"][$module] is set, cause i want to add a module to glpi like administration, tools ...
But i want that only admin can acces to my module, i want to do something like that :

if (Session::haveRight("group","r")) {

but haveright check the module of the session variable and i don"t know where it is, and where i can set a new module

Thanks for your help