for (Row<byte[], byte[], byte[]> r : rows) {
List<HColumn<byte[], byte[]>> cols = r.getColumnSlice().getColumns();
if (cols.isEmpty())
continue;
ObjectIndexKey key = ObjectIndexKey.fromBytes(r.getKey());
Collection<ObjectInfo> list = map.get(key);
if (list == null) {
list = new ArrayList<ObjectInfo>(cols.size());
map.put(key, list);
}