// Verify serializer escape '&' once:
assertFalse(concatUri.toString().contains("&"));
doc.appendChild(concatNode);
HtmlSerializer serializer = new DefaultHtmlSerializer();
String html = serializer.serialize(doc);
assertTrue(html.contains(concatUri.toString().replace("&", "&")));
serializer = new CajaHtmlSerializer();
html = serializer.serialize(doc);
assertTrue(html.contains(concatUri.toString().replace("&", "&")));
}