public static function getRootFolder()
    {
        $filesystem = new Filesystem();
        $folder     = $filesystem->normalizePath(__DIR__ . '/../');

        if (! is_dir($folder)) {
            throw new RuntimeException(
                sprintf(
                    'Could not find a matching folder for folder name "%1$s".',
                    $folder
                )
            );
        }

        return $folder;
    }