}

  @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> {

          assertEquals(expected.asMapOfRanges(), subRangeMap.asMapOfRanges());
          assertEquals(expected.asDescendingMapOfRanges(), subRangeMap.asDescendingMapOfRanges());
          assertEquals(
              ImmutableList.copyOf(subRangeMap.asMapOfRanges().entrySet()).reverse(),
              ImmutableList.copyOf(subRangeMap.asDescendingMapOfRanges().entrySet()));

          if (!expected.asMapOfRanges().isEmpty()) {

              ImmutableMap.of(range1, 1, range2, 2);
          ImmutableMap<Range<Integer>, Integer> asMap = rangeMap.asMapOfRanges();
          ImmutableMap<Range<Integer>, Integer> descendingMap = rangeMap.asDescendingMapOfRanges();
          assertEquals(expectedAsMap, asMap);
          assertEquals(expectedAsMap, descendingMap);
          SerializableTester.reserializeAndAssert(asMap);

        new RegularImmutableSortedSet<>(ranges, Range.<K>rangeLexOrdering());
    return new ImmutableSortedMap<>(rangeSet, values);
  }

  @Override
  public ImmutableMap<Range<K>, V> asDescendingMapOfRanges() {
    if (ranges.isEmpty()) {
      return ImmutableMap.of();
    }
    RegularImmutableSortedSet<Range<K>> rangeSet =

        new RegularImmutableSortedSet<>(ranges, Range.<K>rangeLexOrdering());
    return new ImmutableSortedMap<>(rangeSet, values);
  }

  @Override
  public ImmutableMap<Range<K>, V> asDescendingMapOfRanges() {
    if (ranges.isEmpty()) {
      return ImmutableMap.of();
    }
    RegularImmutableSortedSet<Range<K>> rangeSet =