def unsubscribe(self, callback_id):
        """Ask the hub to cancel the subscription for callback_id, then delete
        it from the local database if successful.

        """
        request = self.get_active_subscription(callback_id)
        request['mode'] = 'unsubscribe'
        self.subscribe_impl(callback_id, **request)
def unsubscribe ( self , callback_id ) : request = self . get_active_subscription ( callback_id ) request [ 'mode' ] = 'unsubscribe' self . subscribe_impl ( callback_id , ** request )
Ask the hub to cancel the subscription for callback_id, then delete
        it from the local database if successful.