public Builder<E> add(E... elements) {
      for (E element : elements) {
        add(element);
      }
      return this;
    }

    /**
     * Adds each element of {@code elements} to the {@code ImmutableCollection} being built.
     *
     * <p>Note that each builder class overrides this method in order to covariantly return its own
     * type.
     *
     * @param elements the elements to add

  // also mean that the iterator returns the head element first, which those
  // don't.

  public Test testsForPriorityBlockingQueue() {
    return QueueTestSuiteBuilder.using(
            new TestStringQueueGenerator() {
              @Override
              public Queue<String> create(String[] elements) {
                return new PriorityBlockingQueue<>(MinimalCollection.of(elements));
              }
            })

    @Override
    protected List<Float> create(Float[] elements) {
      return asList(elements);
    }
  }

  public static final class FloatsAsListHeadSubListGenerator extends TestFloatListGenerator {
    @Override
    protected List<Float> create(Float[] elements) {
      Float[] suffix = {Float.MIN_VALUE, Float.MAX_VALUE};
      Float[] all = concat(elements, suffix);
      return asList(all).subList(0, elements.length);

    @Override
    protected List<Float> create(Float[] elements) {
      return asList(elements);
    }
  }

  public static final class FloatsAsListHeadSubListGenerator extends TestFloatListGenerator {
    @Override
    protected List<Float> create(Float[] elements) {
      Float[] suffix = {Float.MIN_VALUE, Float.MAX_VALUE};
      Float[] all = concat(elements, suffix);
      return asList(all).subList(0, elements.length);

    @Override
    protected List<Integer> create(Integer[] elements) {
      return asList(elements);
    }
  }

  public static final class IntsAsListHeadSubListGenerator extends TestIntegerListGenerator {
    @Override
    protected List<Integer> create(Integer[] elements) {
      Integer[] suffix = {Integer.MIN_VALUE, Integer.MAX_VALUE};
      Integer[] all = concat(elements, suffix);
      return asList(all).subList(0, elements.length);

     * elements (only the first duplicate element is added).
     *
     * @param elements the elements to add
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code elements} is null or contains a null element
     */
    @Override
    @CanIgnoreReturnValue
    public Builder<E> addAll(Iterable<? extends E> elements) {

     *
     * @param delimiter the separator to use between elements
     * @param elements the elements to join
     * @return elements separated by delimiter
     */
    public static String join(final CharSequence delimiter, final CharSequence... elements) {
        final StringBuilder sb = new StringBuilder();
        for (final CharSequence element : elements) {
            if (sb.length() > 0) {

      Comparator<? super E> comparator, E... elements) {
    checkNotNull(elements);
    switch (elements.length) {
      case 0:
        return emptySet(comparator);
      default:
        SortedSet<E> delegate = new TreeSet<E>(comparator);
        for (E element : elements) {
          checkNotNull(element);
          delegate.add(element);
        }

      return ImmutableSet.copyOf(elements);
    }
  }

  public static class DegeneratedImmutableSetGenerator extends TestStringSetGenerator {
    @SuppressWarnings("DistinctVarargsChecker") // deliberately testing deduplication
    @Override
    protected Set<String> create(String[] elements) {
      return ImmutableSet.of(elements[0], elements[0]);
    }
  }

      for (int i = 0; i < 100; i++) {
        Element element = Element.values()[random.nextInt(range)];
        elements.add(element);
        queue.add(element);
      }
      Iterator<Element> queueIterator = queue.iterator();
      int remaining = queue.size();
      while (queueIterator.hasNext()) {
        Element element = queueIterator.next();
        remaining--;