saving permissions as json in Administrator for th

问题:

I am using Administrator (frozennode) with Sentry . for permission part when I want to create new group I dont know how should I save the text "user.update" like {"user.update":1} . I have to .because sentry's methods work just with json data.

but when I import different kind of permissions or groups how do this?

how should I change the Administrator save() method to force it do that just for "permission" field? the save() function -> http://laravel.io/bin/qkr76

thanks for your time