*
   * <p>Cancelling a delegate future propagates to input futures once all the delegates complete,
   * either from cancellation or because an input future has completed. If N futures are passed in,
   * and M delegates are cancelled, the remaining M input futures will be cancelled once N - M of
   * the input futures complete. If all the delegates are cancelled, all the input futures will be

   *
   * <p>Cancelling a delegate future propagates to input futures once all the delegates complete,
   * either from cancellation or because an input future has completed. If N futures are passed in,
   * and M delegates are cancelled, the remaining M input futures will be cancelled once N - M of
   * the input futures complete. If all the delegates are cancelled, all the input futures will be

    SettableFuture<Object> future1 = SettableFuture.create();
    SettableFuture<Object> future2 = SettableFuture.create();
    SettableFuture<Object> future3 = SettableFuture.create();
    ListenableFuture<List<Object>> all = allAsList(future1, future2, future3);

    future1.setException(new MyException());
    future2.setException(new MyException());
    future3.setException(new MyException());

    try {

    SettableFuture<Object> future1 = SettableFuture.create();
    SettableFuture<Object> future2 = SettableFuture.create();
    SettableFuture<Object> future3 = SettableFuture.create();
    ListenableFuture<List<Object>> all = allAsList(future1, future2, future3);

    future1.setException(new MyException());
    future2.setException(new MyException());
    future3.setException(new MyException());

    try {

      // listener, and set this.futures to null.
      // This is not actually a problem, since the foreach only needs this.futures to be non-null
      // at the beginning of the loop.
      int i = 0;
      for (ListenableFuture<? extends InputT> future : futures) {
        int index = i++;
        future.addListener(
            () -> {
              try {
                if (future.isCancelled()) {

 * result. (If you want such access, you may prefer {@link Futures#addCallback
 * Futures.addCallback}.) Still, direct {@code addListener} calls are occasionally useful:
 *
 * <pre>{@code
 * final String name = ...;
 * inFlight.add(name);
 * ListenableFuture<Result> future = service.query(name);
 * future.addListener(new Runnable() {
 *   public void run() {

      // listener, and set this.futures to null.
      // This is not actually a problem, since the foreach only needs this.futures to be non-null
      // at the beginning of the loop.
      int i = 0;
      for (ListenableFuture<? extends InputT> future : futures) {
        int index = i++;
        future.addListener(
            () -> {
              try {
                if (future.isCancelled()) {

 * result. (If you want such access, you may prefer {@link Futures#addCallback
 * Futures.addCallback}.) Still, direct {@code addListener} calls are occasionally useful:
 *
 * <pre>{@code
 * final String name = ...;
 * inFlight.add(name);
 * ListenableFuture<Result> future = service.query(name);
 * future.addListener(new Runnable() {
 *   public void run() {

 * result. (If you want such access, you may prefer {@link Futures#addCallback
 * Futures.addCallback}.) Still, direct {@code addListener} calls are occasionally useful:
 *
 * <pre>{@code
 * final String name = ...;
 * inFlight.add(name);
 * ListenableFuture<Result> future = service.query(name);
 * future.addListener(new Runnable() {
 *   public void run() {

  CollectionFuture(
      ImmutableCollection<? extends ListenableFuture<? extends V>> futures,
      boolean allMustSucceed) {
    super(futures, allMustSucceed, true);

    List<@Nullable Present<V>> values =
        futures.isEmpty()
            ? Collections.<@Nullable Present<V>>emptyList()
            : Lists.<@Nullable Present<V>>newArrayListWithCapacity(futures.size());

    // Populate the results list with null initially.