public function createUseCaseDiagrammFor($entity)
    {
        if (is_int($entity)) {
            $entity = $this->getById($entity);
        } elseif (!$entity instanceof UseCaseEntity) {
            throw new \InvalidArgumentException('Unkown entity data type "' . gettype($entity) . '"');
        }

        $diagrammService = $this->getDiagrammService();

        return $diagrammService->createDiagrammFromNodes(array($entity), UseCaseDiagramm::TYPE_USE_CASE);
    }