public static JPQLQuery<Tuple> selectDistinct(Expression<?>... exprs) {
        return new JPASubQuery<Void>().select(exprs).distinct();
    }
Create a new detached JPQLQuery instance with the given projection

@param exprs projection
@return select(distinct expr)
querydsl-jpa/src/main/java/com/querydsl/jpa/JPAExpressions.java