<http://schema.org/position>
"4"^^<http://www.w3.org/2001/XMLSchema#integer>
<http://product.rakuten.co.jp/product/BUFFALO+WXR-1900DHP/9433d51182348d11a895b2756695dfb6/item/1/1/?sc=1&l2-id=pdt_item_more>