}

  @Override
  public Map<Range<K>, V> asMapOfRanges() {
    return new AsMapOfRanges(entriesByLowerBound.values());
  }

  @Override
  public Map<Range<K>, V> asDescendingMapOfRanges() {
    return new AsMapOfRanges(entriesByLowerBound.descendingMap().values());
  }

  private final class AsMapOfRanges extends IteratorBasedAbstractMap<Range<K>, V> {