public Iterable<String> query(final Filter filter, final String indexName,
final NodeState indexMeta, final String indexStorageNodeName,
final PropertyRestriction pr) {
final NodeState indexState = indexMeta.getChildNode(indexStorageNodeName);
final NodeBuilder index = new ReadOnlyBuilder(indexState);
if (pr.first != null && !pr.first.equals(pr.last)) {
// '>' & '>=' and between use case
ChildNodeEntry firstValueableItem;
String firstValuableItemKey;