public function getEntityByPageAndBusinessIdentifier(BusinessTemplate $page, $entityIdentifier, $attributeName)
    {
        if (!$this->entityManager) {
            throw new \Exception('EntityManager not defined, you should use the "victoire_core.helper.queriable_business_entity_helper" service');
        }
        $entity = null;

        $businessEntityId = $page->getBusinessEntityId();

        $businessEntity = $this->findById($businessEntityId);

        //test the result
        if ($businessEntity === null) {
            throw new \Exception('The business entity ['.$businessEntityId.'] was not found.');
        }

        $entity = $this->findEntityByBusinessEntityAndAttribute($businessEntity, $attributeName, $entityIdentifier);

        //test the result
        if ($entity === null) {
            throw new \Exception('The entity ['.$entityIdentifier.'] was not found.');
        }

        return $entity;
    }