/**
   * A diamond shaped directed graph (arrows going down):
   *
   * <pre>{@code
   *   a
   *  / \
   * b   c
   *  \ /
   *   d
   * }</pre>
   */
  private static final SuccessorsFunction<Character> DIAMOND_GRAPH =
      createDirectedGraph("ab", "ac", "bd", "cd");

  /**
   * Same as {@link #DIAMOND_GRAPH}, but with an extra c->a edge and some self edges:
   *

  /**
   * A diamond shaped directed graph (arrows going down):
   *
   * <pre>{@code
   *   a
   *  / \
   * b   c
   *  \ /
   *   d
   * }</pre>
   */
  private static final SuccessorsFunction<Character> DIAMOND_GRAPH =
      createDirectedGraph("ab", "ac", "bd", "cd");

  /**
   * Same as {@link #DIAMOND_GRAPH}, but with an extra c->a edge and some self edges:
   *

   * use the {@code ArrayList} {@linkplain ArrayList#ArrayList() constructor} directly, taking
   * advantage of <a href="http://goo.gl/iz2Wi">"diamond" syntax</a>.
   */
  @GwtCompatible(serializable = true)
  public static <E extends @Nullable Object> ArrayList<E> newArrayList() {
    return new ArrayList<>();
  }

  /**

   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated. Instead,
   * use the {@code HashSet} constructor directly, taking advantage of <a
   * href="http://goo.gl/iz2Wi">"diamond" syntax</a>.
   */
  public static <E extends @Nullable Object> HashSet<E> newHashSet() {
    return new HashSet<>();
  }

  /**

   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated. Instead,
   * use the {@code HashMap} constructor directly, taking advantage of <a
   * href="http://goo.gl/iz2Wi">"diamond" syntax</a>.
   *
   * @return a new, empty {@code HashMap}
   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      HashMap<K, V> newHashMap() {
    return new HashMap<>();
  }

   *     forth. A {@code null} argument is converted to the four-character string {@code "null"};
   *     non-null values are converted to strings using {@link Object#toString()}.
   * @since 25.1
   */
  // TODO(diamondm) consider using Arrays.toString() for array parameters
  public static String lenientFormat(
      @CheckForNull String template, @CheckForNull @Nullable Object... args) {

  First came ten soldiers carrying clubs; these were all shaped
like the three gardeners, oblong and flat, with their hands and
feet at the corners:  next the ten courtiers; these were
ornamented all over with diamonds, and walked two and two, as the
soldiers did.  After these came the royal children; there were
ten of them, and the little dears came jumping merrily along hand
in hand, in couples:  they were all ornamented with hearts.  Next

   *     forth. A {@code null} argument is converted to the four-character string {@code "null"};
   *     non-null values are converted to strings using {@link Object#toString()}.
   * @since 25.1
   */
  // TODO(diamondm) consider using Arrays.toString() for array parameters
  public static String lenientFormat(
      @CheckForNull String template, @CheckForNull @Nullable Object... args) {

   *
   * @return null if an explanation cannot be provided (e.g. because the future is done).
   * @since 23.0
   */
  @CheckForNull
  protected String pendingToString() {
    // TODO(diamondm) consider moving this into addPendingString so it's always in the output
    if (this instanceof ScheduledFuture) {
      return "remaining delay=["
          + ((ScheduledFuture) this).getDelay(TimeUnit.MILLISECONDS)

  First came ten soldiers carrying clubs; these were all shaped
like the three gardeners, oblong and flat, with their hands and
feet at the corners:  next the ten courtiers; these were
ornamented all over with diamonds, and walked two and two, as the
soldiers did.  After these came the royal children; there were
ten of them, and the little dears came jumping merrily along hand
in hand, in couples:  they were all ornamented with hearts.  Next