for (ScoreDoc hit : getHits(mLucene.getQuery(sf))) {
int docNo = hit.doc;
DBpediaResource resource = getDBpediaResource(docNo);
TermFreqVector vector = getVector(docNo);
surrogates.add(new LuceneFeatureVector(resource, vector));
}
//LOG.debug(surrogates.size()+" surrogates found.");
// return set of surrogates