final int size = valueList.size();
final Map<Long, Data> map = new HashMap<Long, Data>(size);
List<CollectionItem> list = new ArrayList<CollectionItem>(size);
for (Data value : valueList) {
final long itemId = nextId();
list.add(new CollectionItem(itemId, value));
map.put(itemId, value);
}
getCollection().addAll(index, list);
return map;