How can I get statistic data in my custom ribbon rule?

[jerry-yuan]

As the WeightedResponseTimeRule, I tried to get statistic data by AbstractLoadBalancer.getLoadBalancerStats() (like ServerWeight.maintainWeights() do). But both my custom RibbonRule and ServerWeight will get an empty LoadBalancerStats object with all static data of 0.0, and I have make an environment to make different response time far larger with 0ms. The Weighted ResponseTimeRule's weights is always zero and behaved like an RandomRule. I am not sure if there is any configuration swiches to enable statistics.