private Element formatErrors(Document doc, InputSource is,
CharSequence orig, List<Message> messages, boolean visible) {
MessageContext mc = new MessageContext();
Map<InputSource, CharSequence> originalSrc = Maps.newHashMap();
originalSrc.put(is, orig);
mc.addInputSource(is);
SnippetProducer sp = new SnippetProducer(originalSrc, mc);
Element errElement = doc.createElement("ul");
// Style defined in gadgets.css
errElement.setAttribute("class", "gadgets-messages");