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

    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));

    if (elements.isEmpty()) {
      // We avoid allocating anything.
      return of();
    }
    // Collection<E>.toArray() is required to contain only E instances, and all we do is read them.
    // TODO(cpovirk): Consider using Object[] anyway.
    @SuppressWarnings("unchecked")
    E[] array = (E[]) elements.toArray();
    /*
     * For a Set, we guess that it contains no duplicates. That's just a guess for purpose of

    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));

   */
  private void assertSuppressed(Suppression... expected) {
    assertEquals(ImmutableList.copyOf(expected), suppressor.suppressions);
  }

  // TODO(cpovirk): Just use addSuppressed+getSuppressed now that we can rely on it.
  /** Suppressor that records suppressions. */
  private static class TestSuppressor implements Closer.Suppressor {

 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class RegularImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {
  @SuppressWarnings("unchecked") // TODO(cpovirk): Consider storing Entry<?, ?>[] instead.
  static final RegularImmutableBiMap<Object, Object> EMPTY =
      new RegularImmutableBiMap<>(
          null, null, (Entry<Object, Object>[]) ImmutableMap.EMPTY_ENTRY_ARRAY, 0, 0);

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 =

   * 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},