* @param xpath the XPath expression to select elements
     * @param attr the attribute name to extract URLs from
     * @param encoding the character encoding to use
     * @return a list of extracted URLs
     */
    protected List<String> getUrlFromTagAttribute(final URL url, final Document document, final String xpath, final String attr,
            final String encoding) {
        if (logger.isDebugEnabled()) {

                        final NamedNodeMap nnm = parent.getAttributes();

                        for (int i = 0; i < nnm.getLength(); i++) {
                            final Node attr = nnm.item(i);
                            final String aname = attr.getNodeName();
                            final boolean isPrefix = aname.startsWith("xmlns:");

                            if (isPrefix || "xmlns".equals(aname)) {