class NavigableIndex extends AbstractMapBasedAttributeIndex<A, O, ConcurrentNavigableMap<A, StoredResultSet<O>>> implements SortedKeyStatisticsAttributeIndex<A, O>, OnHeapTypeIndex {

    @Override
    public CloseableIterable<KeyStatistics<A>> getStatisticsForDistinctKeys(QueryOptions queryOptions) {
        return super.getStatisticsForDistinctKeys(queryOptions);
    }

    protected  NavigableIndex(Factory<ConcurrentNavigableMap<A, StoredResultSet<O>>> indexMapFactory, Factory<StoredResultSet<O>> valueSetFactory, Attribute<O, A> attribute);

}