CountDownLatch endLatch = new CountDownLatch(threadCount);
        AtomicInteger successCount = new AtomicInteger(0);
        List<Exception> exceptions = Collections.synchronizedList(new ArrayList<>());

        // When - Multiple threads accessing trees concurrently
        for (int t = 0; t < threadCount; t++) {
            final int threadId = t;
            executor.submit(() -> {

        // nothing
    }

    /**
     * A list of Throwables representing failures that occurred during the operation.
     */
    protected List<Throwable> failures = Collections.synchronizedList(new ArrayList<>());

    /**
     * Adds a Throwable to the list of failures.
     *
     * @param t the Throwable to add
     */
    public void addFailure(final Throwable t) {
        failures.add(t);

import org.apache.maven.lifecycle.internal.ProjectSegment;

/**
 */
public class CompletionServiceStub implements CompletionService<ProjectSegment> {
    List<FutureTask<ProjectSegment>> projectBuildFutureTasks = Collections.synchronizedList(new ArrayList<>());

    final boolean finishImmediately;

    public int size() {
        return projectBuildFutureTasks.size();
    }

    public CompletionServiceStub(boolean finishImmediately) {

import org.apache.maven.project.MavenProject;

/**
 */
public class MojoExecutorStub extends MojoExecutor { // This is being lazy instead of making interface

    protected final List<MojoExecution> executions = Collections.synchronizedList(new ArrayList<>());

    public MojoExecutorStub() {
        super(null, null, null, null, null, null);
    }

    public MojoExecutorStub(
            BuildPluginManager pluginManager,

  private static final LazyLogger logger = new LazyLogger(ListenerCallQueue.class);

  // TODO(chrisn): promote AppendOnlyCollection for use here.
  private final List<PerListenerQueue<L>> listeners =
      Collections.synchronizedList(new ArrayList<PerListenerQueue<L>>());

  /** Method reference-compatible listener event. */
  interface Event<L> {
    /** Call a method on the listener. */
    void call(L listener);
  }

  /**

        final int threadCount = 10;
        final int operationsPerThread = 100;
        final ExecutorService executor = Executors.newFixedThreadPool(threadCount);

        final List<Long> timings = Collections.synchronizedList(new ArrayList<>());

        try {
            for (int t = 0; t < threadCount; t++) {
                executor.submit(() -> {
                    for (int i = 0; i < operationsPerThread; i++) {

  private static final LazyLogger logger = new LazyLogger(ListenerCallQueue.class);

  // TODO(chrisn): promote AppendOnlyCollection for use here.
  private final List<PerListenerQueue<L>> listeners =
      Collections.synchronizedList(new ArrayList<PerListenerQueue<L>>());

  /** Method reference-compatible listener event. */
  interface Event<L> {
    /** Call a method on the listener. */
    void call(L listener);
  }

  /**

    return (list instanceof RandomAccess)
        ? new SynchronizedRandomAccessList<E>(list, mutex)
        : new SynchronizedList<E>(list, mutex);
  }

  private static class SynchronizedList<E extends @Nullable Object>
      extends SynchronizedCollection<E> implements List<E> {
    SynchronizedList(List<E> delegate, @Nullable Object mutex) {
      super(delegate, mutex);
    }

    @Override

    return (list instanceof RandomAccess)
        ? new SynchronizedRandomAccessList<E>(list, mutex)
        : new SynchronizedList<E>(list, mutex);
  }

  private static class SynchronizedList<E extends @Nullable Object>
      extends SynchronizedCollection<E> implements List<E> {
    SynchronizedList(List<E> delegate, @Nullable Object mutex) {
      super(delegate, mutex);
    }

    @Override

    /**
     * Thread-safe list of active data crawling threads.
     * Used to track and manage all currently running crawler threads.
     */
    protected final List<DataCrawlingThread> dataCrawlingThreadList = Collections.synchronizedList(new ArrayList<>());

    /**
     * Creates a new instance of DataIndexHelper.
     * This constructor initializes the helper for managing data crawling operations,