StylesClassRuleExtractorFactory stylesClassRuleExtractorFactory =
new StylesClassRuleExtractorFactoryImpl(ruleBuilderFactory);
RuleExtractor classRuleExtractor = new ClassRuleExtractor(
stylesClassRuleExtractorFactory,
OptimalClassNameGenerator.getDefaultInstance());
generator.addRuleExtractor(classRuleExtractor);
// Add the rule group extractor.
RuleExtractor groupRuleExtractor = new GroupRuleExtractor();
generator.addRuleExtractor(groupRuleExtractor);