public function setNullablePositionColumn(SchemaSetupInterface $setup)
    {
        $setup->getConnection()->modifyColumn(
            $setup->getTable('smile_virtualcategory_catalog_category_product_position'),
            'position',
            [
                'type'     => \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
                'nullable' => true,
                'comment'  => 'Position',
            ]
        );
    }