public static <E> AbstractGroupExpression<E, Set<E>> set(Expression<E> expression) {
        return GSet.createLinked(expression);
    }
public static < E > AbstractGroupExpression < E , Set < E > > set ( Expression < E > expression ) { return GSet . createLinked ( expression ) ; }
Create a new aggregating set expression using a backing LinkedHashSet

@param expression values for this expression will be accumulated into a set
@return wrapper expression