if (page == null) {
page = new MapTract("Oops, 404: ${mojasef.request.path.URI}");
StorerHelper.put(context, HTTPConstants.RESPONSE_CODE, "404");
}
StringFinder result = new FetcherStringFinder(
new FallbackFetcher(page.getUnderlyingFetcher(), context.getUnderlyingFetcher()));
Tract template = findTemplate(result);
engine.expandTemplate(context, template, collector);
collector.flush();
}