private static Document toDocument(InputSource in) throws SAXException, IOException {
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    factory.setNamespaceAware(true);
    factory.setIgnoringComments(true);

    DocumentBuilder builder;
    try {
        builder = factory.newDocumentBuilder();
    } catch (ParserConfigurationException e) {
        //should never be thrown because we're not doing anything fancy with the configuration
        throw new RuntimeException(e);
    }

    return builder.parse(in);
}