code: public void shutdownNow() {
          allChannels.close();
          workerGroup.shutdownGracefully();
          bossGroup.shutdownGracefully();
          clientGroup.shutdownGracefully();
          if (pipeliningGroup != null) {
              pipeliningGroup.shutdownGracefully();
          }
      }
docs: This method is for shutting down the connectors without a delay.