Doctrine\ODM\CouchDB\Mapping\MetadataResolver\DoctrineResolver::storeAssociationField PHP Method

    public function storeAssociationField($data, ClassMetadata $class, DocumentManager $dm, $fieldName, $fieldValue)
    {
        $data['doctrine_metadata']['associations'][] = $fieldName;
        $data[$fieldName] = $fieldValue;
        return $data;
    }