ExecutorService service = Executors.newFixedThreadPool(4);
    ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
    try {
      queue.addListener(listener, service);

      final CountDownLatch latch = new CountDownLatch(1);
      Multiset<Object> counters = ConcurrentHashMultiset.create();
      queue.enqueue(incrementingEvent(counters, listener, 1));
      queue.enqueue(incrementingEvent(counters, listener, 2));

  // Signals that the function is waiting to complete
  private CountDownLatch funcIsWaitingLatch;
  // Signals the function so it will complete
  private CountDownLatch funcCompletionLatch;

  @Override
  protected ListenableFuture<String> buildChainingFuture(ListenableFuture<Integer> inputFuture) {
    outputFuture = SettableFuture.create();
    funcIsWaitingLatch = new CountDownLatch(1);
    funcCompletionLatch = new CountDownLatch(1);

 * period or an interrupt while waiting for the expected event will result in a {@link
 * RuntimeException}.
 *
 * <p>Here's an example that tests a {@code finalize} method:
 *
 * <pre>{@code
 * final CountDownLatch latch = new CountDownLatch(1);
 * Object x = new MyClass() {
 *   ...
 *   protected void finalize() { latch.countDown(); ... }
 * };
 * x = null;  // Hint to the JIT that x is stack-unreachable
 * GcFinalization.await(latch);

            .build(computingFunction);

    // seed the map, so its segment's count > 0
    cache.getUnchecked("a");
    shouldWait.set(true);

    final CountDownLatch computationStarted = new CountDownLatch(1);
    final CountDownLatch computationComplete = new CountDownLatch(1);
    new Thread(
            new Runnable() {
              @Override
              public void run() {
                computationStarted.countDown();

 */
public class AbstractExecutionThreadServiceTest extends TestCase {

  private final TearDownStack tearDownStack = new TearDownStack(true);
  private final CountDownLatch enterRun = new CountDownLatch(1);
  private final CountDownLatch exitRun = new CountDownLatch(1);

  private Thread executionThread;
  private Throwable thrownByExecutionThread;
  private final Executor exceptionCatchingExecutor =
      new Executor() {

import java.util.concurrent.CountDownLatch;

import org.apache.maven.execution.DefaultMavenExecutionRequest;
import org.apache.maven.execution.MavenExecutionRequest;
import org.apache.maven.execution.MavenSession;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertNull;

/**
 */
class DefaultLegacySupportTest {
    final CountDownLatch latch = new CountDownLatch(1);

  private final Timeout timeout;
  private final Outcome expectedOutcome;
  private final Monitor monitor;
  private final FlagGuard guard;
  private final CountDownLatch tearDownLatch;
  private final CountDownLatch doingCallLatch;
  private final CountDownLatch callCompletedLatch;

  private GeneratedMonitorTest(
      Method method,
      Scenario scenario,
      boolean fair,
      @Nullable Timeout timeout,

      throws Exception {
    ExecutorService executorService = Executors.newFixedThreadPool(numberOfThreads);
    final CountDownLatch startLatch = new CountDownLatch(numberOfThreads);
    final CountDownLatch doneLatch = new CountDownLatch(numberOfThreads);
    for (int i = numberOfThreads; i > 0; i--) {
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored

  // Signals that the function is waiting to complete
  private CountDownLatch funcIsWaitingLatch;
  // Signals the function so it will complete
  private CountDownLatch funcCompletionLatch;

  @Override
  protected ListenableFuture<String> buildChainingFuture(ListenableFuture<Integer> inputFuture) {
    outputFuture = SettableFuture.create();
    funcIsWaitingLatch = new CountDownLatch(1);
    funcCompletionLatch = new CountDownLatch(1);

    tester.testAllPublicInstanceMethods(new MapMaker());
  }

  @GwtIncompatible // threads
  static final class DelayingIdentityLoader<T> implements Function<T, T> {
    private final CountDownLatch delayLatch;

    DelayingIdentityLoader(CountDownLatch delayLatch) {
      this.delayLatch = delayLatch;
    }

    @Override
    public T apply(T key) {
      awaitUninterruptibly(delayLatch);
      return key;
    }
  }