}

  public static <E> ImmutableList<E> of(E e1) {
    return new SingletonImmutableList<E>(checkNotNull(e1));
  }

  public static <E> ImmutableList<E> of(E e1, E e2) {
    return new RegularImmutableList<E>(ImmutableList.<E>nullCheckedList(e1, e2));
  }

  public static <E> ImmutableList<E> of(E e1, E e2, E e3) {
    return new RegularImmutableList<E>(ImmutableList.<E>nullCheckedList(e1, e2, e3));
  }

  @CollectionSize.Require(SEVERAL)
  public void testRetainAll_countIgnored() {
    resetContainer(getSubjectGenerator().create(e0(), e2(), e1(), e0()));
    assertTrue(getList().retainAll(asList(e0(), e1())));
    assertContentsInOrder(getList(), e0(), e1(), e0());
  }

  }

  public static <E> ImmutableSet<E> of(E e1) {
    return new SingletonImmutableSet<E>(e1);
  }

  @SuppressWarnings("unchecked")
  public static <E> ImmutableSet<E> of(E e1, E e2) {
    return create(e1, e2);
  }

  @SuppressWarnings("unchecked")
  public static <E> ImmutableSet<E> of(E e1, E e2, E e3) {
    return create(e1, e2, e3);
  }

  @SuppressWarnings("unchecked")

  protected <E extends Comparable<? super E>> Set<E> of(E e1, E e2) {
    return ImmutableSet.of(e1, e2);
  }

  @Override
  protected <E extends Comparable<? super E>> Set<E> of(E e1, E e2, E e3) {
    return ImmutableSet.of(e1, e2, e3);
  }

  @Override
  protected <E extends Comparable<? super E>> Set<E> of(E e1, E e2, E e3, E e4) {
    return ImmutableSet.of(e1, e2, e3, e4);
  }

  @Override

  protected <E extends Comparable<? super E>> Set<E> of(E e1, E e2) {
    return ImmutableSet.of(e1, e2);
  }

  @Override
  protected <E extends Comparable<? super E>> Set<E> of(E e1, E e2, E e3) {
    return ImmutableSet.of(e1, e2, e3);
  }

  @Override
  protected <E extends Comparable<? super E>> Set<E> of(E e1, E e2, E e3, E e4) {
    return ImmutableSet.of(e1, e2, e3, e4);
  }

  @Override

    return ofInternal(Ordering.natural(), e1);
  }

  @SuppressWarnings("unchecked")
  public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(E e1, E e2) {
    return ofInternal(Ordering.natural(), e1, e2);
  }

  @SuppressWarnings("unchecked")
  public static <E extends Comparable<? super E>> ImmutableSortedSet<E> of(E e1, E e2, E e3) {

  // TODO: rename e3, e4 => missing1, missing2
  private final E e0;
  private final E e1;
  private final E e2;
  private final E e3;
  private final E e4;

  public SampleElements(E e0, E e1, E e2, E e3, E e4) {
    this.e0 = e0;
    this.e1 = e1;
    this.e2 = e2;
    this.e3 = e3;
    this.e4 = e4;
  }

  @Override
  public Iterator<E> iterator() {

   */
  public static <E> ImmutableMultiset<E> of(E e1) {
    return copyFromElements(e1);
  }

  /**
   * Returns an immutable multiset containing the given elements, in order.
   *
   * @throws NullPointerException if any element is null
   * @since 6.0 (source-compatible since 2.0)
   */
  public static <E> ImmutableMultiset<E> of(E e1, E e2) {
    return copyFromElements(e1, e2);
  }

  /**

    return copyOf(Ordering.natural(), Arrays.asList(e1, e2));
  }

  /**
   * 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) {

                MetadataGraphEdge[] sortedExits = exits.toArray(new MetadataGraphEdge[0]);
                Arrays.sort(sortedExits, (e1, e2) -> {
                    if (e1.getDepth() == e2.getDepth()) {
                        if (e2.getPomOrder() == e1.getPomOrder()) {
                            return e1.getTarget()
                                    .toString()
                                    .compareTo(e2.getTarget().toString());