/**
   * Returns a builder that creates immutable sorted maps whose keys are ordered by their natural
   * ordering. The sorted maps use {@link Ordering#natural()} as the comparator.
   */
  public static <K extends Comparable<?>, V> Builder<K, V> naturalOrder() {
    return new Builder<>(Ordering.natural());
  }

  /**
   * Returns a builder that creates immutable sorted maps with an explicit comparator. If the

        this.sorter = new ProjectSorter(projects);
        this.order = new HashMap<>();
        this.projects = new HashMap<>();
        List<MavenProject> sorted = this.sorter.getSortedProjects();
        for (int index = 0; index < sorted.size(); index++) {
            MavenProject project = sorted.get(index);
            String id = ProjectSorter.getId(project);

   * Returns an immutable sorted multiset containing the given elements sorted by their natural
   * ordering.
   *
   * @throws NullPointerException if any element is null
   */
  public static <E extends Comparable<? super E>> ImmutableSortedMultiset<E> of(
      E e1, E e2, E e3, E e4) {
    return copyOf(Ordering.natural(), Arrays.asList(e1, e2, e3, e4));
  }

  /**

  /**
   * Returns a builder that creates immutable sorted maps whose keys are ordered by their natural
   * ordering. The sorted maps use {@link Ordering#natural()} as the comparator.
   */
  public static <K extends Comparable<?>, V> Builder<K, V> naturalOrder() {
    return new Builder<>(Ordering.natural());
  }

  /**
   * Returns a builder that creates immutable sorted maps with an explicit comparator. If the

      Comparator<? super E> comparator, Collection<? extends E> elements) {
    return copyOf(comparator, (Iterable<? extends E>) elements);
  }

  /**
   * Returns an immutable sorted set containing the elements of a sorted set, sorted by the same
   * {@code Comparator}. That behavior differs from {@link #copyOf(Iterable)}, which always uses the
   * natural ordering of the elements.
   *

      Comparator<? super E> comparator, Collection<? extends E> elements) {
    return copyOf(comparator, (Iterable<? extends E>) elements);
  }

  /**
   * Returns an immutable sorted set containing the elements of a sorted set, sorted by the same
   * {@code Comparator}. That behavior differs from {@link #copyOf(Iterable)}, which always uses the
   * natural ordering of the elements.
   *

  public static class Chars extends SampleElements<Character> {
    public Chars() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super('b', 'a', 'c', 'd', 'e');
    }
  }

  public static class Enums extends SampleElements<AnEnum> {
    public Enums() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super(AnEnum.B, AnEnum.A, AnEnum.C, AnEnum.D, AnEnum.E);
    }

   *   <li>SORTED: ordering according to a supplied comparator is guaranteed.
   * </ul>
   */
  public enum Type {
    UNORDERED,
    STABLE,
    INSERTION,
    SORTED
  }

  private ElementOrder(Type type, @CheckForNull Comparator<T> comparator) {
    this.type = checkNotNull(type);
    this.comparator = comparator;
    checkState((type == Type.SORTED) == (comparator != null));
  }

   *   <li>SORTED: ordering according to a supplied comparator is guaranteed.
   * </ul>
   */
  public enum Type {
    UNORDERED,
    STABLE,
    INSERTION,
    SORTED
  }

  private ElementOrder(Type type, @CheckForNull Comparator<T> comparator) {
    this.type = checkNotNull(type);
    this.comparator = comparator;
    checkState((type == Type.SORTED) == (comparator != null));
  }

   * The returned collection is immutable.
   *
   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method
   * returns a {@link SortedSet}, instead of the {@link Collection} specified in the {@link
   * Multimap} interface.
   *
   * <p>Any duplicates in {@code values} will be stored in the multimap once.
   */
  @CanIgnoreReturnValue
  @Override