protected T instance;

        protected Consumer<T> destroyer;

        protected ComponentHolder(final T instance, final Consumer<T> destroyer) {
            this.instance = instance;
            this.destroyer = destroyer;
        }

        protected T get() {
            return instance;
        }

        protected void destroy() {

        }
        final String commandDestroyTimeoutStr = fessConfig.getSystemProperty("thumbnail.command.destroy.timeout");
        if (commandDestroyTimeoutStr != null) {
            commandDestroyTimeout = Long.parseLong(commandDestroyTimeoutStr);
        }
    }

    @Override
    public void destroy() {
        destoryTimer.cancel();
        destoryTimer = null;
    }

    @Override

    protected final ConcurrentHashMap<String, JobProcess> runningProcessMap = new ConcurrentHashMap<>();

    protected int processDestroyTimeout = 10;

    @PreDestroy
    public void destroy() {
        for (final String sessionId : runningProcessMap.keySet()) {
            if (logger.isInfoEnabled()) {
                logger.info("Stopping process {}", sessionId);
            }

  // clients from directly destroying this object since it may manage its own
  // lifetime through ref counting. Thus clients MUST call Release() in order to
  // destroy an instance of this class.
  virtual void Release() = 0;

  // Creates an operation builder and ties it to this context.
  // The returned object can be used for setting operation's attributes,

    //                                                                           =========
    @Override
    public void rollback() {
        for (MultipartFormFile formFile : elementsFile.values()) {
            formFile.destroy();
        }
    }

    // ===================================================================================
    //                                                                              Finish

    @PreDestroy
    public void destroy() {
        generating = false;
        thumbnailQueueThread.interrupt();
        try {
            thumbnailQueueThread.join(10000);
        } catch (final InterruptedException e) {
            logger.warn("Thumbnail thread is timeouted.", e);
        }
        generatorList.forEach(g -> {
            try {
                g.destroy();
            } catch (final Exception e) {

        onConnectListenerList.add(listener);
    }

    public boolean connected() {
        return connected;
    }

    public void connect() {
        destroy();
        client = createClient();

        final ClusterHealthResponse healthResponse =
                get(c -> c.admin().cluster().prepareHealth(targetIndices).setWaitForYellowStatus().execute());

  // clients from directly destroying this object since it may manage it's own
  // lifetime through ref counting. Thus this must be allocated on the heap and
  // clients MUST call Release() in order to destroy an instance of this class.
  virtual void Release() = 0;

  virtual absl::Status Reset(const char* op, const char* raw_device_name) = 0;

  virtual const string& Name() const = 0;

runModifiers(data.instance.modifiers, data, 'flip');\n    }\n  });\n  return data;\n}\n","// Utils\nimport debounce from './utils/debounce';\nimport isFunction from './utils/isFunction';\n\n// Methods\nimport update from './methods/update';\nimport destroy from './methods/destroy';\nimport enableEventListeners from './methods/enableEventListeners';\nimport disableEventListeners from './methods/disableEventListeners';\nimport Defaults from './methods/defaults';\nimport placements from './methods/placements';\n\nexport...

  // Initialize the step resource container for a training step. This is used
  // in current TF runtime. For tfrt, it is used by fallback op handler.
  virtual void StartStep() = 0;
  // Destroy the step resource container for a training step.
  virtual void EndStep() = 0;

  // Return the Eager Executor for current thread. Please note that Eager
  // Executor is only used in current TF but not in TFRT.