@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() {

              // 1. for long chains of futures strung together with setFuture we consume less stack
              // 2. we avoid allocating Cancellation objects at every level of the cancellation
              //    chain
              // We can only do this for TrustedFuture, because TrustedFuture.cancel is final and
              // does nothing but delegate to this method.
              AbstractFuture<?> trusted = (AbstractFuture<?>) futureToPropagateTo;