protected ServerStats getServerStats(Server server) {
        if (server == null) {
            return null;
        }

        try {
            return serverStatsCache.get(server);
        } catch (ExecutionException e) {
            ServerStats stats = createServerStats(server);
            serverStatsCache.asMap().putIfAbsent(server, stats);
            return serverStatsCache.asMap().get(server);
        }
    }
Method that updates the internal stats of Response times maintained on a per Server
basis
@param server
@param msecs
ribbon-loadbalancer/src/main/java/com/netflix/loadbalancer/LoadBalancerStats.java