code: @Override
  	public IntSetBitStore range(int from, int to) {
  		if (from < 0) throw new IllegalArgumentException();
  		if (to < from) throw new IllegalArgumentException();
  		to += start;
  		if (to > finish) throw new IllegalArgumentException();
  		from += start;
  		SortedSet<Integer> sub;
  		if (to == from) {
  			// seems we have to do this because subSet(x,x) is faulty?
  			sub = Collections.emptySortedSet();
  		} else if (to == start) {
  			sub = from == finish ? set : set.tailSet(from);
  		} else {
  			sub = from == finish ? set.headSet(to) : set.subSet(from, to);
  		}
  		return new IntSetBitStore(sub, from, to, mutable);
  	}
docs: views