return bs;
}
public DocSet getHashDocSet(OpenBitSet bs) {
int[] docs = new int[(int)bs.cardinality()];
BitSetIterator iter = new BitSetIterator(bs);
for (int i=0; i<docs.length; i++) {
docs[i] = iter.next();
}
return new HashDocSet(docs,0,docs.length);
}