polkit.addRule(function(action, subject) {
    if ((action.id == "org.freedesktop.packagekit.package-install" ||
         action.id == "org.freedesktop.packagekit.package-reinstall" ||
         action.id == "org.freedesktop.packagekit.system-update" ||
         action.id == "org.freedesktop.packagekit.upgrade-system") &&
         subject.isInGroup("role-teacher")) {
            return polkit.Result.YES;
    }
});