private static RuleBase readRulesFromXML(String fileName) throws Exception {
final Reader source = new InputStreamReader(new FileInputStream(fileName));
final PackageBuilder builder = new PackageBuilder();
builder.addPackageFromXml(source);
final Package pkg = builder.getPackage();
final RuleBase ruleBase = RuleBaseFactory.newRuleBase();
ruleBase.addPackage(pkg);