*
     * <p>This method is used when testing iterators without a known ordering. We poll the target
     * iterator's next element and pass it to the reference iterator through this method so it can
     * return the same element. This enables the assertion to pass and the reference iterator to
     * properly update its state.
     */
    void promoteToNext(E e) {
      if (nextElements.remove(e)) {

   *       in the {@code exceptions} collection.
   * </ul>
   *
   * <p>Though this method takes any {@link Collection}, it often makes most sense to pass a {@link
   * java.util.List} or some other collection that preserves the order in which the exceptions got
   * added.
   *
   * @throws NullPointerException if {@code exceptions} is null

    Map<K, V> delegateMap = Maps.newHashMapWithExpectedSize(n);
    // If duplicates are allowed, this map will track the last value for each duplicated key.
    // A second pass will retain only the first entry for that key, but with this last value. The
    // value will then be replaced by null, signaling that later entries with the same key should
    // be deleted.

      fail("expected <" + e.getMessage() + "> to contain <" + message + ">");
    }
  }

  /**
   * Test class with valid equals and hashCode methods. Testers created with instances of this class
   * should always pass.
   */
  private static class ValidTestObject {
    private int aspect1;
    private int aspect2;

    ValidTestObject(int aspect1, int aspect2) {
      this.aspect1 = aspect1;
      this.aspect2 = aspect2;

   *
   * <p>This method is declared to accept any 2 {@code Comparable} objects, even if they are not <a
   * href="https://docs.oracle.com/javase/tutorial/collections/interfaces/order.html">mutually
   * comparable</a>. If you pass objects that are not mutually comparable, this method may throw an
   * exception. (The reason for this decision is lost to time, but the reason <i>might</i> be that

    }
  }

  /*
   * Whenever an implementation uses `instanceof` on a parameter instance, the test has to know that
   * (so much for "black box") and try instances that both do and don't pass the check. The "don't"
   * half of that is more awkward to arrange...
   */
  private static <T> Iterable<T> iterable(final Collection<T> collection) {
    // return collection::iterator;
    return new Iterable<T>() {

  private enum SupplierFunctionImpl implements SupplierFunction<@Nullable Object> {
    INSTANCE;

    // Note: This makes T a "pass-through type"
    @Override
    @CheckForNull
    public Object apply(Supplier<@Nullable Object> input) {
      return input.get();
    }

    @Override
    public String toString() {

   * without the guard being satisfied (due to timeout, but not interrupt) can then immediately exit
   * the monitor without signalling. If it timed out without being signalled, it does not need to
   * "pass on" the signal to another thread. If it *was* signalled, then its guard must have been
   * satisfied at the time of signal, and has since been modified by some other thread to be

    }
  }

  /*
   * Whenever an implementation uses `instanceof` on a parameter instance, the test has to know that
   * (so much for "black box") and try instances that both do and don't pass the check. The "don't"
   * half of that is more awkward to arrange...
   */
  private static <T> Iterable<T> iterable(final Collection<T> collection) {
    // return collection::iterator;
    return new Iterable<T>() {

   * int} values are boxed into {@link Integer} instances on demand, which can be very expensive.
   * The returned list should be used once and discarded. For any usages beyond that, pass the
   * returned list to {@link com.google.common.collect.ImmutableList#copyOf(Collection)
   * ImmutableList.copyOf} and use that list instead.
   */
  public List<Integer> asList() {
    /*