Collection<?> collection = (Collection<?>) elements;
        ensureRoomFor(collection.size());
        if (collection instanceof ImmutableCollection) {
          ImmutableCollection<?> immutableCollection = (ImmutableCollection<?>) collection;
          size = immutableCollection.copyIntoArray(contents, size);
          return this;
        }
      }
      super.addAll(elements);
      return this;
    }
  }

import java.util.function.Predicate;
import org.jspecify.annotations.Nullable;

/**
 * GWT emulated version of {@link ImmutableCollection}.
 *
 * @author Jesse Wilson
 */
@SuppressWarnings("serial") // we're overriding default serialization
public abstract class ImmutableCollection<E> extends AbstractCollection<E> implements Serializable {
  static final int SPLITERATOR_CHARACTERISTICS =

    }

    /**
     * Returns a newly-created {@code ImmutableCollection} of the appropriate type, containing the
     * elements provided to this builder.
     *
     * <p>Note that each builder class covariantly returns the appropriate type of {@code
     * ImmutableCollection} from this method.
     */
    public abstract ImmutableCollection<E> build();
  }

import org.jspecify.annotations.Nullable;

/**
 * List returned by {@link ImmutableCollection#asList} that delegates {@code contains} checks to the
 * backing collection.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 */
@GwtCompatible
@SuppressWarnings("serial")
abstract class ImmutableAsList<E> extends ImmutableList<E> {
  abstract ImmutableCollection<E> delegateCollection();

  @Override

  @Override
  public ImmutableCollection<Entry<K, V>> entries() {
    return (ImmutableCollection<Entry<K, V>>) super.entries();
  }

  @Override
  ImmutableCollection<Entry<K, V>> createEntries() {
    return new EntryCollection<>(this);
  }

  private static final class EntryCollection<K, V> extends ImmutableCollection<Entry<K, V>> {
    @Weak final ImmutableMultimap<K, V> multimap;

class RegularImmutableAsList<E> extends ImmutableAsList<E> {
  private final ImmutableCollection<E> delegate;
  private final ImmutableList<? extends E> delegateList;

  RegularImmutableAsList(ImmutableCollection<E> delegate, ImmutableList<? extends E> delegateList) {
    this.delegate = delegate;
    this.delegateList = delegateList;
  }

  RegularImmutableAsList(ImmutableCollection<E> delegate, Object[] array) {
    this(delegate, asImmutableList(array));

class RegularImmutableAsList<E> extends ImmutableAsList<E> {
  private final ImmutableCollection<E> delegate;
  private final ImmutableList<? extends E> delegateList;

  RegularImmutableAsList(ImmutableCollection<E> delegate, ImmutableList<? extends E> delegateList) {
    this.delegate = delegate;
    this.delegateList = delegateList;
  }

  RegularImmutableAsList(ImmutableCollection<E> delegate, Object[] array) {
    this(delegate, asImmutableList(array));

import org.jspecify.annotations.Nullable;

/**
 * List returned by {@link ImmutableCollection#asList} that delegates {@code contains} checks to the
 * backing collection.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 */
@GwtCompatible
@SuppressWarnings("serial")
abstract class ImmutableAsList<E> extends ImmutableList<E> {
  abstract ImmutableCollection<E> delegateCollection();

  @Override

  @Override
  public ImmutableCollection<Entry<K, V>> entries() {
    return (ImmutableCollection<Entry<K, V>>) super.entries();
  }

  @Override
  ImmutableCollection<Entry<K, V>> createEntries() {
    return new EntryCollection<>(this);
  }

  private static final class EntryCollection<K, V> extends ImmutableCollection<Entry<K, V>> {
    @Weak final ImmutableMultimap<K, V> multimap;

   */
  @LazyInit
  private @Nullable ImmutableCollection<? extends ListenableFuture<? extends InputT>> futures;

  private final boolean allMustSucceed;
  private final boolean collectsValues;

  AggregateFuture(
      ImmutableCollection<? extends ListenableFuture<? extends InputT>> futures,
      boolean allMustSucceed,
      boolean collectsValues) {