<?xml version="1.0"?>
<p1:root main="10" xmlns:p2="urn:imported" xmlns:p1="urn:main" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:main keyref-main.xsd">
    <p2:items id="1">
        <item index="1"/>
        <item index="2" parent="1"/>
        <item index="3" parent="1"/>
        <item index="4" parent="2"/>
    </p2:items>
    <p2:items id="2">
        <item index="1"/>
        <item index="2" parent="1"/>
        <item index="3" parent="1"/>
        <item index="4" parent="2"/>
    </p2:items>
</p1:root>
