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

   */
  public <E1 extends E> NetworkBuilder<N, E1> edgeOrder(ElementOrder<E1> edgeOrder) {
    NetworkBuilder<N, E1> newBuilder = cast();
    newBuilder.edgeOrder = checkNotNull(edgeOrder);
    return newBuilder;
  }

  /** Returns an empty {@link MutableNetwork} with the properties of this {@link NetworkBuilder}. */
  public <N1 extends N, E1 extends E> MutableNetwork<N1, E1> build() {

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

  /**
   * Returns an immutable list containing the given elements, in order.
   *
   * @throws NullPointerException if any element is null
   */
  public static <E> ImmutableList<E> of(E e1, E e2) {
    return construct(e1, e2);
  }

  /**

    return ImmutableSortedSet.of(e1, e2);
  }

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

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

  @Override

    return ImmutableSortedSet.of(e1, e2);
  }

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

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

  @Override

  protected abstract <E extends Comparable<? super E>> Set<E> of(E e1, E e2, E e3);

  protected abstract <E extends Comparable<? super E>> Set<E> of(E e1, E e2, E e3, E e4);

  protected abstract <E extends Comparable<? super E>> Set<E> of(E e1, E e2, E e3, E e4, E e5);

  protected abstract <E extends Comparable<? super E>> Set<E> of(
      E e1, E e2, E e3, E e4, E e5, E e6, E... rest);

   * inserted into the multiset must implement the {@code Comparable} interface. Furthermore, all
   * such elements must be <i>mutually comparable</i>: {@code e1.compareTo(e2)} must not throw a
   * {@code ClassCastException} for any elements {@code e1} and {@code e2} in the multiset. If the
   * user attempts to add an element to the multiset that violates this constraint (for example, the

                    sessionCache.size(), maxSize, toRemove);

            // Remove oldest sessions
            sessionCache.entrySet()
                    .stream()
                    .sorted((e1, e2) -> e1.getValue().getLastAccessedAt().compareTo(e2.getValue().getLastAccessedAt()))
                    .limit(toRemove)
                    .map(Map.Entry::getKey)
                    .collect(Collectors.toList())

            @Override
            protected List<EventInfo> fetchNewEvents() {
                final EventInfo e1 = new EventInfo();
                e1.name = "event1";
                final EventInfo e2 = new EventInfo();
                e2.name = "event2";
                return List.of(e1, e2);
            }

            @Override
            protected void dispatchEvent(final EventInfo event) {