valueHolder.name = checkNotNull(name);
      return this;
    }

    // Holder object for values that might be null and/or empty.
    static class ValueHolder {
      @Nullable String name;
      @Nullable Object value;
      @Nullable ValueHolder next;
    }

    /**
     * Holder object for values that cannot be null or empty (will be printed unconditionally). This

    this.forward = forward;
  }

  @Override
  public int count(@Nullable Object element) {
    return forward.count(element);
  }

  @Override
  public @Nullable Entry<E> firstEntry() {
    return forward.lastEntry();
  }

  @Override
  public @Nullable Entry<E> lastEntry() {
    return forward.firstEntry();
  }

  @Override
  public int size() {

   */

  @LazyInit private @Nullable ListenableFuture<V> delegateRef;
  @LazyInit private @Nullable ScheduledFuture<?> timer;

  private TimeoutFuture(ListenableFuture<V> delegate) {
    this.delegateRef = Preconditions.checkNotNull(delegate);
  }

  /** A runnable that is called when the delegate or the timer completes. */
  private static final class Fire<V extends @Nullable Object> implements Runnable {

import java.util.Map;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Creates maps, containing sample elements, to be tested.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@NullMarked
public interface TestMapGenerator<K extends @Nullable Object, V extends @Nullable Object>
    extends TestContainerGenerator<Map<K, V>, Map.Entry<K, V>> {
  K[] createKeyArray(int length);

   * <p>The pointers in [size(), entries.length) are all "null" (UNSET).
   */
  private transient int @Nullable [] entries;

  /**
   * The elements contained in the set, in the range of [0, size()). The elements in [size(),
   * elements.length) are all {@code null}.
   */
  @VisibleForTesting transient @Nullable Object @Nullable [] elements;

  /**

    assertMultimapRemainsUnmodified(multimap, originalEntries);
  }

  private static <E extends @Nullable Object> void assertCollectionsAreEquivalent(
      Collection<E> expected, Collection<E> actual) {
    assertIteratorsInOrder(expected.iterator(), actual.iterator());
  }

  private static <K extends @Nullable Object, V extends @Nullable Object>
      void assertMultimapRemainsUnmodified(Multimap<K, V> expected, List<Entry<K, V>> actual) {

  ListenableScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit);

  /**
   * @since 15.0 (previously returned ScheduledFuture)
   */
  @Override
  <V extends @Nullable Object> ListenableScheduledFuture<V> schedule(
      Callable<V> callable, long delay, TimeUnit unit);

  /**
   * @since 15.0 (previously returned ScheduledFuture)
   */
  @Override
  ListenableScheduledFuture<?> scheduleAtFixedRate(

 * invoke methods, they invoke methods on the {@code ForwardingListMultimap}.
 *
 * @author Kurt Alfred Kluever
 * @since 3.0
 */
@GwtCompatible
public abstract class ForwardingListMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends ForwardingMultimap<K, V> implements ListMultimap<K, V> {

  /** Constructor for use by subclasses. */
  protected ForwardingListMultimap() {}

  @Override

  }

  @GwtIncompatible // not present in emulated superclass
  @Override
  int copyIntoArray(@Nullable Object[] dst, int offset) {
    return delegateList.copyIntoArray(dst, offset);
  }

  @Override
  @Nullable Object @Nullable [] internalArray() {
    return delegateList.internalArray();
  }

  @Override
  int internalArrayStart() {

 */
@GwtCompatible
public abstract class AbstractSequentialIterator<T> extends UnmodifiableIterator<T> {
  private @Nullable T nextOrNull;

  /**
   * Creates a new iterator with the given first element, or, if {@code firstOrNull} is null,
   * creates a new empty iterator.
   */
  protected AbstractSequentialIterator(@Nullable T firstOrNull) {
    this.nextOrNull = firstOrNull;
  }

  /**