// Use the same key for every URL from this domain
GroupedUrlDatum datum;
while ((datum = _urls.poll()) != null) {
ScoredUrlDatum scoreUrl;
FetchCounters counter;
String url = datum.getUrl();
if (isDeferred) {
counter = FetchCounters.URLS_DEFERRED;
scoreUrl = new ScoredUrlDatum(url, GroupingKey.DEFERRED_GROUPING_KEY, UrlStatus.SKIPPED_DEFERRED, 0.0);