Ngcordova push unregister android

I’m trying to unregister an app from the Google Push Notification. According to ngcordova, I need to pass some options

   // WARNING: dangerous to unregister (results in loss of tokenID)
$cordovaPush.unregister(options).then(function(result) {
  // Success!
}, function(err) {
  // Error
})

as documented on http://ngcordova.com/docs/plugins/pushNotifications/

So … what are the options?