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

    @Override
    public void run() {
      // This prevents cancellation from propagating because we don't call setFuture(delegate) until
      // delegate is already done, so calling cancel() on this future won't affect it.
      ListenableFuture<V> localDelegate = delegate;
      if (localDelegate != null) {
        setFuture(localDelegate);
      }
    }

    @Override
    @CheckForNull