AgendaItem item = (AgendaItem) knowledgeHelper.getMatch();
final Cheese cheese = (Cheese) item.getTuple().getHandle().getObject();
final int oldPrice = cheese.getPrice();
cheese.setPrice(100);
item.setActivationUnMatchListener(new ActivationUnMatchListener() {
public void unMatch(org.kie.api.runtime.rule.RuleRuntime wm,
Match activation) {
cheese.setPrice(oldPrice);
}