public static function getCertificateBundle()
    {
        $bundle = dirname(__FILE__) . DIRECTORY_SEPARATOR . 'Certificates' . DIRECTORY_SEPARATOR . 'ca-bundle.pem';

        if (!file_exists($bundle)) {
            throw new \Genesis\Exceptions\InvalidArgument(
                'CA Bundle file is missing or inaccessible'
            );
        }

        return $bundle;
    }