<?xml version="1.0" encoding="UTF-8"?>
<productsInStores>
<product id="1" store_id="1"/>
<product id="1" store_id="2"/>
<product id="1" store_id="3"/>
<product id="2" store_id="1"/>
<product id="2" store_id="2"/>
<product id="2" store_id="3"/>
</productsInStores>