docs: public static void update(Registry registry) {
      Iterator<Map.Entry<Id, Object>> iter = registry.state().entrySet().iterator();
      while (iter.hasNext()) {
        Map.Entry<Id, Object> entry = iter.next();
        if (entry.getValue() instanceof AbstractMeterState) {
          AbstractMeterState tuple = (AbstractMeterState) entry.getValue();
          tuple.doUpdate(registry);
          if (tuple.hasExpired()) {
            iter.remove();
          }
        }
      }
    }