ListenableFuture<V> future) {
    if (future.isDone()) {
      return future;
    }
    NonCancellationPropagatingFuture<V> output = new NonCancellationPropagatingFuture<>(future);
    future.addListener(output, directExecutor());
    return output;
  }

  /** A wrapped future that does not propagate cancellation to its delegate. */

   * @since 23.0
   */
  @CheckForNull
  protected String pendingToString() {
    // TODO(diamondm) consider moving this into addPendingString so it's always in the output
    if (this instanceof ScheduledFuture) {
      return "remaining delay=["
          + ((ScheduledFuture) this).getDelay(TimeUnit.MILLISECONDS)
          + " ms]";
    }
    return null;
  }