public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
   if (Config.checkFunctionSwitch(invoker, invocation)) {
     logger.info("[{}] had [{}] breaker", localHost, breakCounterMap.size());
     return wrapBreakerInvoke(invoker, invocation);
   }
   Result result = invoker.invoke(invocation);
   toBeNormal(invoker, invocation);
   return result;
 }