// deal with extensions
List<Extension> installedExts = new ArrayList<>();
for (String extName : extensionFactory.getAvailableExtensions().keySet())
{
installedExts.add(new JsrExtension(extName));
}
List<Extension> requestedExts = new ArrayList<>();
for (ExtensionConfig reqCfg : req.getExtensions())
{
requestedExts.add(new JsrExtension(reqCfg));
}
List<Extension> usedExts = configurator.getNegotiatedExtensions(installedExts,requestedExts);
List<ExtensionConfig> configs = new ArrayList<>();
if (usedExts != null)
{