code: @Override
      protected void stopInner() {
          /*
           * TODO REST-Server Need to handle inflight operations. What happens to
           * the existing async operations when a channel.close() is issued in
           * Netty?
           */
          if(this.nettyServerChannel != null) {
              this.nettyServerChannel.close();
          }
  
          if(allChannels != null) {
              allChannels.close().awaitUninterruptibly();
          }
          this.bootstrap.releaseExternalResources();
      }
docs: Closes the Netty Channel and releases all resources