* number of elements and every element of {@code iterator1} is equal to the corresponding element
   * of {@code iterator2}.
   *
   * <p>Note that this will modify the supplied iterators, since they will have been advanced some
   * number of elements forward.
   */
  public static boolean elementsEqual(Iterator<?> iterator1, Iterator<?> iterator2) {
    while (iterator1.hasNext()) {
      if (!iterator2.hasNext()) {

          // Inline the Comparator implementation rather than transforming with a Function
          // to save code size.
          Arrays.sort(
              entryArray,
              0,
              size,
              (e1, e2) -> {
                // requireNonNull is safe because the first `size` elements have been filled in.
                requireNonNull(e1);
                requireNonNull(e2);

 * them, even though they usually won't be needed. If you have such arguments, use the conventional
 * if/throw idiom instead.
 *
 * <p>Depending on your message arguments, memory may be allocated for boxing and varargs array
 * creation. However, the methods of this class have a large number of overloads that prevent such
 * allocations in many common cases.
 *

    // computation is in progress; asMap shouldn't have changed
    assertEquals(1, map.size());
    assertFalse(map.containsKey(getKey));
    assertSame(refreshKey, map.get(refreshKey));

    // let computation complete
    letGetFinishSignal.countDown();
    getFinishedSignal.await();
    checkNothingLogged();

    // asMap view should have been updated
    assertEquals(2, cache.size());

        } while (oldHead != Waiter.TOMBSTONE);
      }
      // re-read value, if we get here then we must have observed a TOMBSTONE while trying to add a
      // waiter.
      // requireNonNull is safe because value is always set before TOMBSTONE.
      return getDoneValue(requireNonNull(value));
    }
    // If we get here then we have remainingNanos < SPIN_THRESHOLD_NANOS and there is no node on the
    // waiters list

@ElementTypesAreNonnullByDefault
public final class Futures extends GwtFuturesCatchingSpecialization {

  // A note on memory visibility.
  // Many of the utilities in this class (transform, withFallback, withTimeout, asList, combine)
  // have two requirements that significantly complicate their design.
  // 1. Cancellation should propagate from the returned future to the input future(s).
  // 2. The returned futures shouldn't unnecessarily 'pin' their inputs after completion.

          // Inline the Comparator implementation rather than transforming with a Function
          // to save code size.
          Arrays.sort(
              entryArray,
              0,
              size,
              (e1, e2) -> {
                // requireNonNull is safe because the first `size` elements have been filled in.
                requireNonNull(e1);
                requireNonNull(e2);

   */
  private static <E> void verifyLinkedHashSetContents(
      LinkedHashSet<E> set, Collection<E> contents) {
    assertEquals(
        "LinkedHashSet should have preserved order for iteration",
        new ArrayList<E>(set),
        new ArrayList<E>(contents));
    verifySetContents(set, contents);
  }

  /**

 * href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a>. Its API is designed to make it a
 * nearly drop-in replacement. It requires Java 8+, and is not available for Android or GWT/J2CL,
 * and may have <a href="https://github.com/ben-manes/caffeine/wiki/Guava">different (usually
 * better) behavior</a> when multiple threads attempt concurrent mutations. Its equivalent to {@code
 * CacheBuilder} is its <a

   * @param typeParam the parameter type variable
   * @param typeArg the actual type to substitute
   */
  /*
   * TODO(cpovirk): Is there any way for us to support TypeParameter instances for type parameters
   * that have nullable bounds? Unfortunately, if we change the parameter to TypeParameter<? extends
   * @Nullable X>, then users might pass a TypeParameter<Y>, where Y is a subtype of X, while still