@Test
public void testGetStatisticsForDistinctKeysDescending(){

    IndexedCollection<Car> collection = new ConcurrentIndexedCollection<Car>();
    SortedKeyStatisticsIndex<String, Car> MANUFACTURER_INDEX = NavigableIndex.onAttribute(Car.MANUFACTURER);
    collection.addIndex(MANUFACTURER_INDEX);
    collection.addAll(CarFactory.createCollectionOfCars(20));
    Set<KeyStatistics<String>> keyStatistics = setOf(MANUFACTURER_INDEX.getStatisticsForDistinctKeysDescending(noQueryOptions()));
    Assert.assertEquals(setOf(
                    new KeyStatistics<String>("Toyota", 6),
                    new KeyStatistics<String>("Honda", 6),
                    new KeyStatistics<String>("Ford", 6),
                    new KeyStatistics<String>("BMW", 2)
            ),
            keyStatistics);
}