private Predicate buildPredicate(ComparisonExpression comparison, Root entityRoot, CriteriaBuilder cb)
{
QueryBuilder qb = queryBuilders.get(comparison.getSelector());
if(qb == null)
throw new BadRequestException(String.format("Can not query by %s",comparison.getSelector()));
return qb.buildPredicate(entityRoot,cb,comparison.getOperator(),comparison.getArgument());
}