private function getRelative($path, $against)
    {
        $relative = null;

        if (preg_replace(',/$,', '', $path) == $against ||
            Path::isBasePath($against, Path::getDirectory($path))
        ) {
            $relative = Path::makeRelative($path, $against);
            $relative = $relative ? '/'.$relative : '';
        }

        return $relative;
    }