public function actionIndex()
    {
        $searchModel = new Z1UserSearch();
        $dataProvider = $searchModel->search(Yii::$app->request->queryParams);

        $pageSize = intval(trim(Yii::$app->request->get('per-page')));

        if ($pageSize) {
            $dataProvider->pagination->pageSize = $pageSize;
        }

        return $this->render('index', [
            'searchModel' => $searchModel,
            'dataProvider' => $dataProvider,
        ]);
    }