protected function validateVcsRepositories($index, $repo)
    {
        if ('package' === $repo['type']) {
            return;
        }

        if (false === strpos($repo['type'], '-')) {
            throw new \UnexpectedValueException('Repository '.$index.' ('.json_encode($repo).') must have a type defined in this way: "%asset-type%-%type%"');
        }
        if (!isset($repo['url'])) {
            throw new \UnexpectedValueException('Repository '.$index.' ('.json_encode($repo).') must have a url defined');
        }
    }