* turn, and does not create any threads of its own.
   *
   * <p>After execution begins on a thread from the {@code delegate} {@link Executor}, tasks are
   * polled and executed from a task queue until there are no more tasks. The thread will not be
   * released until there are no more tasks to run.
   *
   * <p>If a task is submitted while a thread is executing tasks from the task queue, the thread

            );
            task.getDocsDirectory().convention(extension.getDocumentationRenderedRoot());
            task.getPort().convention(webserverPort);

            task.dependsOn(extension.getRenderedDocumentation());
        });

        tasks.register("docs", task -> {
            task.setDescription("Generates all documentation");
            task.setGroup("documentation");

            task.getDocumentationRoot().convention(extension.getUserManual().getStagedDocumentation());
            task.getJavadocRoot().convention(layout.getBuildDirectory().dir("javadoc"));
            task.dependsOn(tasks.named("javadocAll"));
        });

        tasks.named(LifecycleBasePlugin.CHECK_TASK_NAME, task -> task.dependsOn(checkDeadInternalLinks));
    }

        final Tuple3<String, String, String> task = new Tuple3<>(getName(), thumbnailId, path);
        if (logger.isDebugEnabled()) {
            logger.debug("Create thumbnail task: {}", task);
        }
        return task;
    }

    @Override
    public boolean generate(final String thumbnailId, final File outputFile) {

                final Tuple3<String, String, String> task = generator.createTask(path, docMap);
                if (task != null) {
                    if (logger.isDebugEnabled()) {
                        logger.debug("Add thumbnail task: {}", task);
                    }
                    if (!thumbnailTaskQueue.offer(task)) {
                        logger.warn("Failed to add thumbnail task: {}", task);
                    }

        Thread.sleep(10);
        int count = expiredCount;
        task.stop();
        TimeoutManager.getInstance().start();
        assertNotNull(TimeoutManager.getInstance().thread);
        Thread.sleep(2000);
        assertEquals(count, expiredCount);
        assertEquals(1, TimeoutManager.getInstance().getTimeoutTaskCount());
        task.cancel();
        Thread.sleep(2000);

            final TimeoutTask task = e.getElement();
            if (task.isCanceled()) {
                e.remove();
            } else if (!task.isStopped() && task.isExpired()) {
                expiredTask.add(task);
                if (!task.isPermanent()) {
                    e.remove();
                }
            }
        }

    }

    public static void execute(final Runnable task) {
        ForkJoinPool.commonPool().execute(() -> {
            final Thread currentThread = Thread.currentThread();
            final ClassLoader orignal = currentThread.getContextClassLoader();
            currentThread.setContextClassLoader(CommonPoolUtil.class.getClassLoader());
            try {
                task.run();
            } catch (final Exception e) {

                            pool.shutdown();
                        }
                        return true;
                    }
                };
                pool.submit(task);
                return task;
            });
            result = future.get();
        } catch (Exception e) {
            throw new UnresolvableModelException(e, parent.getGroupId(), parent.getArtifactId(), parent.getVersion());

    private static final String NUMBER_OF_PENDING_TASKS = "number_of_pending_tasks";
    private static final String NUMBER_OF_IN_FLIGHT_FETCH = "number_of_in_flight_fetch";
    private static final String DELAYED_UNASSIGNED_SHARDS = "delayed_unassigned_shards";
    private static final String TASK_MAX_WAIT_TIME_IN_QUEUE_IN_MILLIS = "task_max_waiting_in_queue_millis";