<foo>
<bar a="1"/>
<bar a="1" b="2"/>
<bar a="1" b="2" c="3"/>
<bar a="1" b="2" c="3" d="4"/>
<bar a="1" b="2" c="3" d="4" e="5"/>
<bar a="1" b="2" c="3" d="4" e="5" f="6"/>
<bar a="1" b="2" c="3"/>
<bar a="1"/>
</foo>