1.  启动了3个provider , 然后consumer端pi配置为广播调用
![image](https://user-images.githubusercontent.com/42512469/190076093-477e5e50-f870-4928-ac9a-38abbb487cb1.png)

执行用例后并未发现有报错信息输出 , 但是只会有一个provider收到消息且固定为这一个, 当把这个provider下线后,就会从剩余的2个provider中再选一个进行调用,provider会输出内容,另一个还是调不到.然后再把这个下线,剩余的那一个也可以被调到了.
我看代码是进入了BroadcastClusterInvoker了,拿到的invokers列表size=3,进入了for循环3次 但是就是没啥效果 不报错 也调不到全部provider.

2.   另外问一下,broadcast2 这种模式被移除了吗 ,我配broadcast2提示我找不到扩展 can`t find extentions xxx

![image](https://user-images.githubusercontent.com/42512469/190076654-1ed16d04-937d-45c2-8b65-e7f7b335d2fe.png)

打一下断点,输出的信息可以表明是识别到了3个provider了
![image](https://user-images.githubusercontent.com/42512469/190077753-64238317-aff3-4918-8d96-9fee6b82a15b.png)


import org.apache.dubbo.rpc.Result;
import org.apache.dubbo.rpc.RpcContext;
import org.apache.dubbo.rpc.RpcException;
import org.apache.dubbo.rpc.RpcInvocation;
import org.apache.dubbo.rpc.cluster.Directory;
import org.apache.dubbo.rpc.cluster.LoadBalance;
import java.util.List;
import static org.apache.dubbo.rpc.Constants.ASYNC_KEY;
/**
 * BroadcastClusterInvoker
 */
public class BroadcastClusterInvoker<T> extends AbstractClusterInvoker<T> {
    private static final Logger logger = LoggerFactory.getLogger(BroadcastClusterInvoker.class);
    private static final String BROADCAST_FAIL_PERCENT_KEY = "broadcast.fail.percent";
    private static final int MAX_BROADCAST_FAIL_PERCENT = 100;
    private static final int MIN_BROADCAST_FAIL_PERCENT = 0;
    public BroadcastClusterInvoker(Directory<T> directory) {
        super(directory);
    }
    @Override
    @SuppressWarnings({"unchecked", "rawtypes"})
    public Result doInvoke(final Invocation invocation, List<Invoker<T>> invokers, LoadBalance loadbalance) throws RpcException {
        checkInvokers(invokers, invocation);
        RpcContext.getServiceContext().setInvokers((List) invokers);
        RpcException exception = null;
        Result result = null;
        URL url = getUrl();
        
        // 
        //