/**
   * Wraps a {@code Callable} for submission to the underlying executor. This method is also applied
   * to any {@code Runnable} passed to the default implementation of {@link #wrapTask(Runnable)}.
   */
  protected abstract <T extends @Nullable Object> Callable<T> wrapTask(Callable<T> callable);

  /**
   * Wraps a {@code Runnable} for submission to the underlying executor. The default implementation
   * delegates to {@link #wrapTask(Callable)}.

import com.google.common.util.concurrent.AbstractFutureBenchmarks.Facade;
import com.google.common.util.concurrent.AbstractFutureBenchmarks.Impl;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.Executor;
import org.jspecify.annotations.NullUnmarked;

/** Measures the size of AbstractFuture implementations. */
@NullUnmarked
public class AbstractFutureFootprintBenchmark {

  enum State {
    NOT_DONE,

    executor.shutdown();
    assertTrue(executor.isShutdown());
    assertThrows(RejectedExecutionException.class, () -> executor.submit(doNothingRunnable));
    assertFalse(executor.isTerminated());

    // WAIT #2
    barrier.await(1, SECONDS);
    assertFalse(executor.awaitTermination(20, MILLISECONDS));

    // WAIT #3
    barrier.await(1, SECONDS);
    assertTrue(executor.awaitTermination(1, SECONDS));

        int iterations = 1000;
        ExecutorService executor = Executors.newFixedThreadPool(2);
        CountDownLatch endLatch = new CountDownLatch(2);
        AtomicInteger successCount = new AtomicInteger(0);
        List<Exception> exceptions = Collections.synchronizedList(new ArrayList<>());

        // Thread 1: Continuously adds trees
        executor.submit(() -> {
            try {

   */
  public static <V extends @Nullable Object> ListenableFuture<V> listenInPoolThread(
      Future<V> future, Executor executor) {
    checkNotNull(executor);
    if (future instanceof ListenableFuture) {
      return (ListenableFuture<V>) future;
    }
    return new ListenableFutureAdapter<>(future, executor);
  }

  /**
   * An adapter to turn a {@link Future} into a {@link ListenableFuture}. This will wait on the

      assertEquals(Service.State.STOPPING, state());
      shutdownCalled++;
    }

    @Override
    protected Executor executor() {
      return executor;
    }

    @Override
    public void tearDown() throws Exception {
      executor.shutdown();
    }
  }

    SettableFuture<?> future = SettableFuture.create();
    Executor delegate =
        new Executor() {
          @Override
          public void execute(Runnable task) {
            if (future.set(null)) {
              awaitUninterruptibly(latch);
            }
            throw new RejectedExecutionException();
          }
        };
    SequentialExecutor executor = new SequentialExecutor(delegate);

public final class SimpleTimeLimiter implements TimeLimiter {

  private final ExecutorService executor;

  private SimpleTimeLimiter(ExecutorService executor) {
    this.executor = checkNotNull(executor);
  }

  /**
   * Creates a TimeLimiter instance using the given executor service to execute method calls.
   *
   * <p><b>Warning:</b> using a bounded executor may be counterproductive! If the thread pool fills

@NullUnmarked
public class ExecutionSequencerTest extends TestCase {

  ExecutorService executor;

  private ExecutionSequencer serializer;
  private SettableFuture<@Nullable Void> firstFuture;
  private TestCallable firstCallable;

  @Override
  public void setUp() throws Exception {
    executor = newCachedThreadPool();
    serializer = ExecutionSequencer.create();
    firstFuture = SettableFuture.create();

      final Runnable runnable;
      final Executor executor;

      RunnableExecutorPair(Runnable runnable, Executor executor) {
        this.runnable = runnable;
        this.executor = executor;
      }

      void execute() {
        try {
          executor.execute(runnable);
        } catch (RuntimeException e) {
          log.log(
              Level.SEVERE,