"RuntimeException while executing runnable " + command + " with executor " + executor,
            e);
      }
    }
  }

  private final class SetFuture implements Runnable {
    final ListenableFuture<? extends V> delegate;

    SetFuture(ListenableFuture<? extends V> delegate) {
      this.delegate = delegate;
    }

    @Override
    public void run() {
      if (isCancelled()) {

        if (task instanceof SetFuture) {
          SetFuture<?> setFuture = (SetFuture<?>) task;
          // We unwind setFuture specifically to avoid StackOverflowErrors in the case of long
          // chains of SetFutures
          // Handling this special case is important because there is no way to pass an executor to
          // setFuture, so a user couldn't break the chain by doing this themselves.  It is also