protected function isIntegerKey($current, $model): bool
    {
        if ($model != null && $model instanceof Model) {
            return !empty($model->{self::ROW_NUM_COLUMN}) || $model->getKeyType() == 'int';
        } else {
            if ($current != null && is_numeric($current) || ctype_digit($current)) {
                return true;
            }
        }
        return false;
    }