code: private Where<ExtendedRelation, Long> addToWhere(
  			QueryBuilder<ExtendedRelation, Long> qb,
  			Where<ExtendedRelation, Long> where) {
  		if (where == null) {
  			where = qb.where();
  		} else {
  			where.and();
  		}
  		return where;
  	}
docs: Add to the where clause, either as new or with an and
  
  @param qb
  query builder
  @param where
  where clause
  @return where clause