private function xmlLoadString($xmlString)
    {
        libxml_clear_errors();
        libxml_use_internal_errors(true);
        $xml = simplexml_load_string($xmlString);

        if ($errors = libxml_get_errors()) {
            throw new \RuntimeException('Failed to parse OFX: ' . var_export($errors, true));
        }

        return $xml;
    }