import java.util.logging.Level;

/**
 * A list of listeners for implementing a concurrency friendly observable object.
 *
 * <p>Listeners are registered once via {@link #addListener} and then may be invoked by {@linkplain
 * #enqueue enqueueing} and then {@linkplain #dispatch dispatching} events.
 *
 * <p>The API of this class is designed to make it easy to achieve the following properties
 *
 * <ul>

          }
        });
  }

  /**
   * Invokes the subscriber method. This method can be overridden to make the invocation
   * synchronized.
   */
  @VisibleForTesting
  void invokeSubscriberMethod(Object event) throws InvocationTargetException {
    try {
      method.invoke(target, checkNotNull(event));
    } catch (IllegalArgumentException e) {

    @Override
    protected @Nullable Object handleInvocation(
        Object p, Method calledMethod, @Nullable Object[] args) throws Throwable {
      assertEquals(method, calledMethod);
      assertEquals(method + " invoked more than once.", 0, called.get());
      for (int i = 0; i < passedArgs.length; i++) {
        assertEquals(
            "Parameter #" + i + " of " + method + " not forwarded", passedArgs[i], args[i]);
      }

    /**
     * Invokes the method and returns its result.
     *
     * @param <T>
     *            the return type of the method
     * @param target
     *            the target object. Must not be {@literal null}
     * @param args
     *            the method arguments
     * @return the result of the method
     */
    <T> T invoke(Object target, Object... args);

    /**

   *
   * <p>Cancellation does not propagate from the output future to a callable that has begun to
   * execute, but if the output future is cancelled before {@link Callable#call()} is invoked,
   * {@link Callable#call()} will not be invoked.
   */
  public <T extends @Nullable Object> ListenableFuture<T> submit(
      Callable<T> callable, Executor executor) {
    checkNotNull(callable);
    checkNotNull(executor);

                Arguments.of(-1, -2L, -3L, -4L, -5L) // negative values
        );
    }

    // --- Mockito interaction: verify each getter is invoked and returns stubbed values ---
    @Test
    void mockitoMock_verifiesGetterInteractions() {
        // Arrange: mock and stub each getter with distinct values

    @Override
    protected @Nullable Object handleInvocation(
        Object p, Method calledMethod, @Nullable Object[] args) throws Throwable {
      assertEquals(method, calledMethod);
      assertEquals(method + " invoked more than once.", 0, called.get());
      for (int i = 0; i < passedArgs.length; i++) {
        assertEquals(
            "Parameter #" + i + " of " + method + " not forwarded", passedArgs[i], args[i]);
      }

   *
   * <p>Cancellation does not propagate from the output future to a callable that has begun to
   * execute, but if the output future is cancelled before {@link Callable#call()} is invoked,
   * {@link Callable#call()} will not be invoked.
   */
  public <T extends @Nullable Object> ListenableFuture<T> submit(
      Callable<T> callable, Executor executor) {
    checkNotNull(callable);
    checkNotNull(executor);

import java.util.logging.Level;

/**
 * A list of listeners for implementing a concurrency friendly observable object.
 *
 * <p>Listeners are registered once via {@link #addListener} and then may be invoked by {@linkplain
 * #enqueue enqueueing} and then {@linkplain #dispatch dispatching} events.
 *
 * <p>The API of this class is designed to make it easy to achieve the following properties
 *
 * <ul>

internal abstract class ConnectionListener {
  /**
   * Invoked as soon as a call causes a connection to be started.
   */
  open fun connectStart(
    route: Route,
    call: Call,
  ) {}

  /**
   * Invoked when a connection fails to be established.
   */
  open fun connectFailed(
    route: Route,
    call: Call,
    failure: IOException,
  ) {}

  /**
   * Invoked as soon as a connection is successfully established.