Ddd\Application\Service\TransactionalApplicationService::execute PHP Method

    public function execute($request = null)
    {
        if (empty($this->service)) {
            throw new \LogicException('A use case must be specified');
        }
        $operation = function () use($request) {
            return $this->service->execute($request);
        };
        return $this->session->executeAtomically($operation);
    }