class MQClientInstance {

    public boolean registerProducer(final String group, final DefaultMQProducerImpl producer) {
        if (null == group || null == producer) {
            return false;
        }

        MQProducerInner prev = this.producerTable.putIfAbsent(group, producer);
        if (prev != null) {
            log.warn("the producer group[{}] exist already.", group);
            return false;
        }

        return true;
    }

    public  MQClientInstance(ClientConfig clientConfig, int instanceIndex, String clientId);
    public  MQClientInstance(ClientConfig clientConfig, int instanceIndex, String clientId, RPCHook rpcHook);

}