int remaining = queue.size();
      while (queueIterator.hasNext()) {
        Integer element = queueIterator.next();
        remaining--;
        assertThat(elements).contains(element);
        if (random.nextBoolean()) {
          elements.remove(element);
          queueIterator.remove();
        }
      }
      assertThat(remaining).isEqualTo(0);
      assertIntact(queue);

                .map(project -> project.getGroupId() + ":" + project.getArtifactId())
                .collect(Collectors.toList());

        if (remainingProjects.isEmpty()) {
            LOGGER.info("No remaining projects found, resuming the build would not make sense.");
            return Optional.empty();
        }

        return Optional.of(new BuildResumptionData(remainingProjects));
    }

      int remaining = queue.size();
      while (queueIterator.hasNext()) {
        Integer element = queueIterator.next();
        remaining--;
        assertThat(elements).contains(element);
        if (random.nextBoolean()) {
          elements.remove(element);
          queueIterator.remove();
        }
      }
      assertThat(remaining).isEqualTo(0);
      assertIntact(queue);

      E e1, E e2, E e3, E e4, E e5, E e6, E... remaining) {
    Comparable<?>[] contents = new Comparable<?>[6 + remaining.length];
    contents[0] = e1;
    contents[1] = e2;
    contents[2] = e3;
    contents[3] = e4;
    contents[4] = e5;
    contents[5] = e6;
    arraycopy(remaining, 0, contents, 6, remaining.length);
    return construct(Ordering.natural(), contents.length, (E[]) contents);

      E e1, E e2, E e3, E e4, E e5, E e6, E... remaining) {
    Comparable<?>[] contents = new Comparable<?>[6 + remaining.length];
    contents[0] = e1;
    contents[1] = e2;
    contents[2] = e3;
    contents[3] = e4;
    contents[4] = e5;
    contents[5] = e6;
    arraycopy(remaining, 0, contents, 6, remaining.length);
    return construct(Ordering.natural(), contents.length, (E[]) contents);

      if (localTimer != null) {
        long delay = localTimer.getDelay(MILLISECONDS);
        // Negative delays look confusing in an error message
        if (delay > 0) {
          message += ", remaining delay=[" + delay + " ms]";
        }
      }
      return message;
    }
    return null;
  }

  @Override
  protected void afterDone() {

   * @param array the array of elements to append
   * @return an array whose size is one larger than {@code array}, with {@code element} occupying
   *     the first position, and the elements of {@code array} occupying the remaining elements.
   */
  public static <T extends @Nullable Object> T[] concat(@ParametricNullness T element, T[] array) {
    T[] result = newArray(array, array.length + 1);
    result[0] = element;

   * @param array the array of elements to append
   * @return an array whose size is one larger than {@code array}, with {@code element} occupying
   *     the first position, and the elements of {@code array} occupying the remaining elements.
   */
  public static <T extends @Nullable Object> T[] concat(@ParametricNullness T element, T[] array) {
    T[] result = newArray(array, array.length + 1);
    result[0] = element;

        .addEqualityGroup(EnumBiMap.create(ImmutableMap.of(Currency.DOLLAR, Country.CHILE)))
        .addEqualityGroup(EnumBiMap.create(ImmutableMap.of(Currency.FRANC, Country.CANADA)))
        .testEquals();
  }

  /* Remaining behavior tested by AbstractBiMapTest. */

  }

  private static final class UnknownElementException extends RuntimeException {
    private UnknownElementException(Collection<?> expected, Object actual) {
      super("Returned value '" + actual + "' not found. Remaining elements: " + expected);
    }

    private static final long serialVersionUID = 0;
  }

  /**
   * Quasi-implementation of {@link ListIterator} that works from a list of elements and a set of