Field's name attribute does not work for the update queries

class Test 
{
.
.
.
/**
 * @EmbedOne(targetDocument="Location", name="l")
*/
private $location;
.
.
.
}

/** @EmbeddedDocument */
class Location
{
    /**
	 * @Field(type="float", name="y")
	 */
    public $lat;

    /**
	 * @Field(type="float", name="x")
	 */
    public $lng;

	public function __construct($latitude,$longitude) {
		$this->lat = $latitude;
		$this->lng = $longitude;
	}
}

$dm->createQueryBuilder('Test')
->update()
->field('id')->equals(123)
->field('l')->set(new Location(39, 32);
->getQuery(array('upsert' => true))
->execute();

"l": {
    "lat": 39,
    "lng": 32
},

however, it should be

"l": {
    "y": 39,
    "x": 32
},

$dm->createQueryBuilder('Test')
->update()
->field('id')->equals(123)
->field('location')->set(new Location(39, 32);
->getQuery(array('upsert' => true))
->execute();