@Override
    public Map<Connection, ResponseCommand> invokeToGroupAllConnections(final String group,
        final RequestCommand command, final long time, final TimeUnit timeUnit) throws InterruptedException,
        NotifyRemotingException {
        return this.remotingClient.invokeToGroupAllConnections(group, command, time, timeUnit);
    }
Whether to enable loopback connection for metaq client, default is false.
metamorphosis-client/src/main/java/com/taobao/metamorphosis/client/RemotingClientWrapper.java