I'm using DoctrineMongoDBOBundle with Symfony2.

I've a Document Product which has an annotation referenceOne to other Document Price.

I want to sort by price when I fetch with queryBuilder.

```
$qb = $dm->createQueryBuilder('MyBundle:Product')
->field('geocoordinates')
->near('lat','lon')
->sort('hasPrice','desc')

```

But this doesn't works. Perhaps for the use of near?

It depends of toString() method of Document Price?

Regards.