public function listPushSubscriptions(
        $page = 1,
        $per_page = 100,
        $order_by = DataSift_Push_Subscription::ORDERBY_CREATED_AT,
        $order_dir = DataSift_Push_Subscription::ORDERDIR_ASC,
        $include_finished = false
    ) {
        return DataSift_Push_Subscription::listSubscriptions(
            $this,
            $page,
            $per_page,
            $order_by,
            $order_dir,
            $include_finished
        );
    }