<script src="../include.js"></script>
<script>
    test(() => {
        let xmlDoc = new DOMParser().parseFromString(
            '<?xml version="1.0" encoding="UTF-8"?><root xmlns="http://www.w3.org/1999/xhtml"><element Attribute="Value">Text</element></root>',
            'text/xml'
        );

        let element = xmlDoc.querySelector('element');
        println(new XMLSerializer().serializeToString(element));
        element.toggleAttribute('Attribute');
        println(new XMLSerializer().serializeToString(element));
        element.toggleAttribute('Attribute');
        println(new XMLSerializer().serializeToString(element));
    });
</script>