assertEquals("", joiner.join(array));

    StringBuilder sb1FromIterable = new StringBuilder();
    assertSame(sb1FromIterable, joiner.appendTo(sb1FromIterable, set));
    assertEquals(0, sb1FromIterable.length());

    StringBuilder sb1FromIterator = new StringBuilder();
    assertSame(sb1FromIterator, joiner.appendTo(sb1FromIterator, set));

   * separator between each, to {@code builder}. Identical to {@link #appendTo(Appendable,
   * Iterable)}, except that it does not throw {@link IOException}.
   */
  @CanIgnoreReturnValue
  public final StringBuilder appendTo(
      StringBuilder builder, Iterable<? extends @Nullable Object> parts) {
    return appendTo(builder, parts.iterator());
  }

  /**

  abstract Cut<C> withUpperBoundType(BoundType boundType, DiscreteDomain<C> domain);

  abstract void describeAsLowerBound(StringBuilder sb);

  abstract void describeAsUpperBound(StringBuilder sb);

  @CheckForNull
  abstract C leastValueAbove(DiscreteDomain<C> domain);

  @CheckForNull
  abstract C greatestValueBelow(DiscreteDomain<C> domain);

  /*

  static final Tree h = new Tree('h', d, e, g);

  static String iterationOrder(Iterable<? extends Node> iterable) {
    StringBuilder builder = new StringBuilder();
    for (Node t : iterable) {
      builder.append(t.value);
    }
    StringBuilder forEachBuilder = new StringBuilder();
    iterable.forEach(t -> forEachBuilder.append(t.value));
    assertTrue(

    assertEquals("", joiner.join(array));

    StringBuilder sb1FromIterable = new StringBuilder();
    assertSame(sb1FromIterable, joiner.appendTo(sb1FromIterable, set));
    assertEquals(0, sb1FromIterable.length());

    StringBuilder sb1FromIterator = new StringBuilder();
    assertSame(sb1FromIterator, joiner.appendTo(sb1FromIterator, set));

    utf8Lengths.put(MIN_SUPPLEMENTARY_CODE_POINT, 4);
    utf8Lengths.put(MAX_CODE_POINT, 4);

    Integer[] codePoints = utf8Lengths.keySet().toArray(new Integer[] {});
    StringBuilder sb = new StringBuilder();
    Random rnd = new Random();
    for (int trial = 0; trial < 100; trial++) {
      sb.setLength(0);
      int utf8Length = 0;
      for (int i = 0; i < 6; i++) {

  abstract Cut<C> withUpperBoundType(BoundType boundType, DiscreteDomain<C> domain);

  abstract void describeAsLowerBound(StringBuilder sb);

  abstract void describeAsUpperBound(StringBuilder sb);

  @CheckForNull
  abstract C leastValueAbove(DiscreteDomain<C> domain);

  @CheckForNull
  abstract C greatestValueBelow(DiscreteDomain<C> domain);

  /*

    }

    @Override
    @CheckForNull
    public Type getOwnerType() {
      return ownerType;
    }

    @Override
    public String toString() {
      StringBuilder builder = new StringBuilder();
      if (ownerType != null && JavaVersion.CURRENT.jdkTypeDuplicatesOwnerName()) {
        builder.append(JavaVersion.CURRENT.typeName(ownerType)).append('.');
      }
      return builder

        sb.append(o);
      }
    }
    return sb.append(']').toString();
  }

  /** Returns best-effort-sized StringBuilder based on the given collection size. */
  static StringBuilder newStringBuilderForCollection(int size) {
    checkNonnegative(size, "size");
    return new StringBuilder((int) Math.min(size * 8L, Ints.MAX_POWER_OF_TWO));
  }

  /**

    if (related != null & isCancelled()) {
      related.cancel(wasInterrupted());
    }
  }

  @Override
  public String toString() {
    StringBuilder builder = new StringBuilder().append(super.toString()).append("[status=");
    if (isCancelled()) {
      builder.append("CANCELLED");
    } else if (isDone()) {
      addDoneString(builder);
    } else {