actsLikeIteratorHelper(emptyList());
  }

  public void testPeekingIteratorBehavesLikeIteratorOnSingletonIterable() {
    actsLikeIteratorHelper(singletonList(new Object()));
  }

  // TODO(cpovirk): instead of skipping, use a smaller number of steps
  @GwtIncompatible // works but takes 5 minutes to run
  public void testPeekingIteratorBehavesLikeIteratorOnThreeElementIterable() {

   * process it; all should produce the same answer, the only difference should be the number of
   * process()/processRemaining() invocations, due to alignment.
   */
  @AndroidIncompatible // slow. TODO(cpovirk): Maybe just reduce iterations under Android.
  public void testExhaustive() throws Exception {
    Random random = new Random(0); // will iteratively make more debuggable, each time it breaks

   */
  @J2ktIncompatible
  @GwtIncompatible // java.util.concurrent.ScheduledExecutorService
  @IgnoreJRERequirement // Users will use this only if they're already using Duration.
  // TODO(cpovirk): Return ListenableScheduledFuture?
  public static <O extends @Nullable Object> ListenableFuture<O> scheduleAsync(
      AsyncCallable<O> callable, Duration delay, ScheduledExecutorService executorService) {

import org.jspecify.annotations.NullUnmarked;

/**
 * Class that contains nested abstract tests for filtered collection views, along with their
 * implementation helpers.
 *
 * @author Louis Wasserman
 */
/*
 * TODO(cpovirk): Should all the tests for filtered collections run under GWT, too? Currently, they
 * don't.
 */
@NullUnmarked
public final class FilteredCollectionsTestUtil {
  private static final Predicate<Integer> EVEN =

      checkNonNegative(--successorCount);

      if (orderedNodeConnections != null) {
        orderedNodeConnections.remove(new NodeConnection.Succ<>((N) node));
      }
    }

    /*
     * TODO(cpovirk): `return (V) removedValue` once our checker permits that.
     *
     * (We promoted a class of warnings into errors because sometimes they indicate real problems.

        .forAllPublicStaticMethods(Suppliers.class)
        .testNulls();
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection
  @AndroidIncompatible // TODO(cpovirk): ClassNotFoundException: com.google.common.base.Function
  public void testSuppliersSerializable() throws Exception {
    new ClassSanityTester()
        .setDefault(Duration.class, Duration.ofSeconds(1))

        .forAllPublicStaticMethods(Suppliers.class)
        .testNulls();
  }

  @J2ktIncompatible
  @GwtIncompatible // reflection
  @AndroidIncompatible // TODO(cpovirk): ClassNotFoundException: com.google.common.base.Function
  public void testSuppliersSerializable() throws Exception {
    new ClassSanityTester()
        .setDefault(Duration.class, Duration.ofSeconds(1))

   * methods to accept null. We could avoid having unchecked casts in Converter.java itself if we
   * could perform a cast to LegacyConverter, but we can't because it's an internal-only class.
   *
   * TODO(cpovirk): So make it part of the open-source build, albeit package-private there?
   *
   * So we use uncheckedCastNullableTToT here. This is a weird usage of that method: The method is

   */
  protected void shutDown() throws Exception {}

  /**
   * Returns the {@link Scheduler} object used to configure this service. This method will only be
   * called once.
   */
  // TODO(cpovirk): @ForOverride
  protected abstract Scheduler scheduler();

  /**
   * Returns the {@link ScheduledExecutorService} that will be used to execute the {@link #startUp},

    return !tooLow(t) && !tooHigh(t);
  }

  /**
   * Returns the intersection of the two ranges, or an empty range if their intersection is empty.
   */
  @SuppressWarnings("nullness") // TODO(cpovirk): Add casts as needed. Will be noisy and annoying...
  GeneralRange<T> intersect(GeneralRange<T> other) {
    checkNotNull(other);
    checkArgument(comparator.equals(other.comparator));