public function saveGridPage()
    {
        if (!isset(Yii::$app->session[$this->sessionVarName])) {
            Yii::$app->session[$this->sessionVarName] = 0;
        }
        if (!isset(Yii::$app->session[$this->sessionPageSizeName]))
            Yii::$app->session[$this->sessionPageSizeName] = 10;

        if (Yii::$app->request->get($this->getVarName) !== null) {
            Yii::$app->session[$this->sessionVarName] = (int)Yii::$app->request->get($this->getVarName) - 1;
        }
        if (Yii::$app->request->get($this->getPageSizeName) !== null)
            Yii::$app->session[$this->sessionPageSizeName] = (int)Yii::$app->request->get($this->getPageSizeName);
    }