}

  /** Returns an immutable copy of the specified {@code RangeSet}. */
  public static <C extends Comparable> ImmutableRangeSet<C> copyOf(RangeSet<C> rangeSet) {
    checkNotNull(rangeSet);
    if (rangeSet.isEmpty()) {
      return of();
    } else if (rangeSet.encloses(Range.all())) {
      return all();
    }

    if (rangeSet instanceof ImmutableRangeSet) {

    }
    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 =

    TreeRangeSet<C> result = create();
    result.addAll(rangeSet);
    return result;
  }

  /**
   * Returns a {@code TreeRangeSet} representing the union of the specified ranges.
   *
   * <p>This is the smallest {@code RangeSet} which encloses each of the specified ranges. An
   * element will be contained in this {@code RangeSet} if and only if it is contained in at least

      @Override
      <K extends Comparable<K>> RangeSet<K> create(RangeSet<K> contents) {
        return TreeRangeSet.create(contents);
      }
    },
    ImmutableRangeSetImpl {
      @Override
      <K extends Comparable<K>> RangeSet<K> create(RangeSet<K> contents) {
        return ImmutableRangeSet.copyOf(contents);
      }
    };

    abstract <K extends Comparable<K>> RangeSet<K> create(RangeSet<K> contents);
  }

        // Create EnumSet with range
        EnumSet<CrawlerStatus> rangeSet = EnumSet.range(CrawlerStatus.INITIALIZING, CrawlerStatus.RUNNING);
        assertEquals(2, rangeSet.size());
        assertTrue(rangeSet.contains(CrawlerStatus.INITIALIZING));
        assertTrue(rangeSet.contains(CrawlerStatus.RUNNING));
        assertFalse(rangeSet.contains(CrawlerStatus.DONE));
    }

    /**
     * Test switch statement usage

    }
    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 =