protected List<T> currentResults() {
        return results == null ? Collections.emptyList()
            : Collections.unmodifiableList(results);
    }
protected List < T > currentResults ( ) { return results == null ? Collections . emptyList ( ) : Collections . unmodifiableList ( results ) ; }
Allows access to the intermediate result before the
completion of the event.

@return the intermediate results (which may be an empty list)