The new launcher

Maybe I'm doing something wrong or missing something but with the new launcher I can't play the snapshots offline. I don't have access to the internet at home so I have to download the snapshots and play offline. With the new launcher I am unable to do that as there is no "play offline" option. I know the MagicLauncher has that option but I haven't been able to figure out how or if I can play the snapshots with that.