private URL getProxyUrl(URL realURL) {
URL baseRealURL = URLUtils.getUrlBase(realURL);
URL baseProxyURL = urlMapping().getProxyURL(baseRealURL);
URL proxyURL = URLUtils.buildUrl(baseProxyURL, realURL.getPath());
requireProxy.fire(new RequireProxy(baseRealURL, baseProxyURL));
return proxyURL;
}