.that(input)
        .isNotInstanceOf(ListenableFuture.class);
    ListenableFuture<String> listenable = listenInPoolThread(input);
    /*
     * This will occur before the waiting get() in the
     * listenInPoolThread-spawned thread completes:
     */
    RecordingRunnable earlyListener = new RecordingRunnable();
    listenable.addListener(earlyListener, directExecutor());

    input.allowGetToComplete.countDown();

        .that(input)
        .isNotInstanceOf(ListenableFuture.class);
    ListenableFuture<String> listenable = listenInPoolThread(input);
    /*
     * This will occur before the waiting get() in the
     * listenInPoolThread-spawned thread completes:
     */
    RecordingRunnable earlyListener = new RecordingRunnable();
    listenable.addListener(earlyListener, directExecutor());

    input.allowGetToComplete.countDown();

import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Used to test listenable future implementations.
 *
 * @author Sven Mawson
 */
@NullUnmarked
@GwtIncompatible
@J2ktIncompatible
public class ListenableFutureTester {

  private final ExecutorService exec;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Used to test listenable future implementations.
 *
 * @author Sven Mawson
 */
@NullUnmarked
@GwtIncompatible
@J2ktIncompatible
public class ListenableFutureTester {

  private final ExecutorService exec;