@Override
      boolean isCancelled() {
        return true;
      }

      @Override
      void maybeThrowOnGet(@Nullable Throwable cause) throws ExecutionException {
        // TODO(cpovirk): chain in a CancellationException created at the cancel() call?
        throw new CancellationException();
      }
    };

    boolean isDone() {
      return true;
    }

    boolean isCancelled() {

                      : Cancellation.CAUSELESS_CANCELLED);
      AbstractFuture<?> abstractFuture = this;
      while (true) {
        if (ATOMIC_HELPER.casValue(abstractFuture, localValue, valueToSet)) {
          rValue = true;
          complete(abstractFuture, mayInterruptIfRunning);
          if (localValue instanceof SetFuture) {