* @since 23.0
   */
  public static ContiguousSet<Long> closedOpen(long lower, long upper) {
    return create(Range.closedOpen(lower, upper), DiscreteDomain.longs());
  }

  final DiscreteDomain<C> domain;

  ContiguousSet(DiscreteDomain<C> domain) {
    super(Ordering.natural());
    this.domain = domain;
  }

  @Override
  public ContiguousSet<C> headSet(C toElement) {

   * @since 23.0
   */
  public static ContiguousSet<Long> closedOpen(long lower, long upper) {
    return create(Range.closedOpen(lower, upper), DiscreteDomain.longs());
  }

  final DiscreteDomain<C> domain;

  ContiguousSet(DiscreteDomain<C> domain) {
    super(Ordering.natural());
    this.domain = domain;
  }

  @Override
  public ContiguousSet<C> headSet(C toElement) {

      extends TestIntegerSortedSetGenerator {
    static final ContiguousSet<Integer> checkedCreate(SortedSet<Integer> elementsSet) {
      List<Integer> elements = new ArrayList<>(elementsSet);
      /*
       * A ContiguousSet can't have holes. If a test demands a hole, it should be changed so that it
       * doesn't need one, or it should be suppressed for ContiguousSet.
       */
      for (int i = 0; i < elements.size() - 1; i++) {

        .addEqualityGroup(
            ContiguousSet.create(Range.closed(1, 3), integers()),
            ContiguousSet.closed(1, 3),
            ContiguousSet.create(Range.closedOpen(1, 4), integers()),
            ContiguousSet.closedOpen(1, 4),
            ContiguousSet.create(Range.openClosed(0, 3), integers()),
            ContiguousSet.create(Range.open(0, 4), integers()),
            ContiguousSet.create(Range.closed(1, 3), NOT_EQUAL_TO_INTEGERS),

        .addEqualityGroup(
            ContiguousSet.create(Range.closed(1, 3), integers()),
            ContiguousSet.closed(1, 3),
            ContiguousSet.create(Range.closedOpen(1, 4), integers()),
            ContiguousSet.closedOpen(1, 4),
            ContiguousSet.create(Range.openClosed(0, 3), integers()),
            ContiguousSet.create(Range.open(0, 4), integers()),
            ContiguousSet.create(Range.closed(1, 3), NOT_EQUAL_TO_INTEGERS),

        long total = 0;
        for (Range<C> range : ranges) {
          if (range.contains(c)) {
            return Ints.saturatedCast(total + ContiguousSet.create(range, domain).indexOf(c));
          } else {
            total += ContiguousSet.create(range, domain).size();
          }
        }
        throw new AssertionError("impossible");
      }
      return -1;
    }

    @Override

   *       other words, {@code ContiguousSet.create(a.canonical(domain), domain).equals(
   *       ContiguousSet.create(a, domain))}
   *   <li>uniqueness: unless {@code a.isEmpty()}, {@code ContiguousSet.create(a,
   *       domain).equals(ContiguousSet.create(b, domain))} implies {@code
   *       a.canonical(domain).equals(b.canonical(domain))}

        .testEquals();
  }

  /** Returns a {@link Set} with a {@link Set#size()} of {@code size}. */
  private static ContiguousSet<Integer> setSize(int size) {
    checkArgument(size >= 0);
    ContiguousSet<Integer> set = ContiguousSet.closedOpen(0, size);
    checkState(set.size() == size);
    return set;
  }

  /**

 * be as expected on discrete ranges. See the Javadoc of those methods for details.
 *
 * <p>For a {@link Set} whose contents are specified by a {@link Range}, see {@link ContiguousSet}.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#rangeset">RangeSets</a>.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman

        return ImmutableSortedSet.copyOf(contents);
      }
    },
    ContiguousSetImpl {
      @Override
      public <E extends Comparable<E>> Set<E> create(Collection<E> contents) {
        return ContiguousSet.copyOf(contents);
      }
    },
    ;
  }

  public enum ListMultimapImpl {
    ArrayListMultimapImpl {
      @Override
      <K, V> ListMultimap<K, V> create(Multimap<K, V> contents) {