}
else if (p instanceof Stylesheet)
{
Stylesheet parentElem = (Stylesheet) p;
isExtension = parentElem.containsExtensionElementURI(uri);
if ((false == isExtension) && (null != uri)
&& (uri.equals(Constants.S_BUILTIN_EXTENSIONS_URL)
|| uri.equals(Constants.S_BUILTIN_OLD_EXTENSIONS_URL)))
{