private final CloseableList closeables;
  private final FluentFuture<V> future;

  private ClosingFuture(ListenableFuture<V> future) {
    this(future, new CloseableList());
  }

  private ClosingFuture(ListenableFuture<V> future, CloseableList closeables) {
    this.future = FluentFuture.from(future);
    this.closeables = closeables;
  }

  /**

     * should throw IllegalStateException only when they use static state.
     *
     * Why do we deviate here? The answer: We want for fluentFuture.getDone() to throw the same
     * exception as Futures.getDone(fluentFuture).
     */
    checkState(future.isDone(), "Future was expected to be done: %s", future);
    return getUninterruptibly(future);
  }

  /**