tests/Fixtures/schemas/acme/blog/mixin/has-comments/latest.xml
<?xml version="1.0" encoding="UTF-8" ?>
<pbj-schema xmlns="http://gdbots.io/pbj/xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://gdbots.io/pbj/xsd http://gdbots.io/pbj/xsd/schema.xsd">
<schema id="pbj:acme:blog:mixin:has-comments:1-0-0" mixin="true"/>
</pbj-schema>