public function preserveAs()
    {
        $arguments = $this->getArguments();

        if (! isset($arguments['preserve'])) {
            throw new QueryException('You need to specify how this repository should be preserved [single, multiple or default].');
        }

        if (! in_array($arguments['preserve'], ['single', 'multiple', 'default'])) {
            throw new QueryException('Repository can be preserved only as single, multiple or default.');
        }

        return $arguments['preserve'];
    }