@Override
    public Object setAttributeIfAbsent(final String group, final String key, final Object value) {
        return this.remotingClient.setAttributeIfAbsent(group, key, value);
    }
Whether to enable loopback connection for metaq client, default is false.
metamorphosis-client/src/main/java/com/taobao/metamorphosis/client/RemotingClientWrapper.java