@Override
protected void process(Entity e, int accumulatedDelta) {
Expiration expiration = expirationMapper.get(e);
expiration.reduceLifeTime(accumulatedDelta);
if (expiration.isExpired()) {
world.deleteEntity(e);
} else if (expiration.getLifeTime() < smallestLifeTime) {
smallestLifeTime = expiration.getLifeTime();