protected function calculateUuid()
    {
        try {
            // Generate a version 4 (random) UUID object
            $uuid4 = Uuid::uuid4();
            $uuid  = $uuid4->toString();
        } catch (UnsatisfiedDependencyException $exception) {
            throw new Doozr_Registry_Exception($exception->getMessage(), $exception->getCode(), $exception);
        }

        return $uuid;
    }