class ScenarioSimulationXMLPersistence {

    public String extractVersion(String rawXml) {
        Matcher m = p.matcher(rawXml);

        if (m.find()) {
            return m.group(1);
        }
        throw new IllegalArgumentException("Impossible to extract version from the file");
    }

    private  ScenarioSimulationXMLPersistence();

}