String uri = XLinkSupport.getXLinkHref(paintElement);
if (uri.length() == 0) {
return null; // no xlink:href found, exit
}
// check if there is circular dependencies
SVGOMDocument doc = (SVGOMDocument)paintElement.getOwnerDocument();
ParsedURL purl = new ParsedURL(doc.getURL(), uri);
if (!purl.complete())
throw new BridgeException(paintElement,
ERR_URI_MALFORMED,
new Object[] {uri});