code: public static MessageDto initClient(String appName, String labelName) {
          InitClientParams initClientParams = new InitClientParams();
          initClientParams.setAppName(appName);
          initClientParams.setLabelName(labelName);
          MessageDto messageDto = new MessageDto();
          messageDto.setData(initClientParams);
          messageDto.setAction(MessageConstants.ACTION_INIT_CLIENT);
          return messageDto;
      }
docs: 初始化客户端请求
  
  @param appName   appName
  @param labelName labelName
  @return MessageDto