@Override
public DocIdSet getDocIdSet(AtomicReaderContext context, Bits acceptDocs) throws IOException {
AtomicReader reader = context.reader();
Object key = reader.getCoreCacheKey();
DocIdSet docIdSet = _cache.get(key);
if (docIdSet != null) {
_hits.incrementAndGet();
return BitsFilteredDocIdSet.wrap(docIdSet, acceptDocs);
}
// This will only allow a single instance be created per reader per filter