T instance = invoke(factory, args);
    if (instance == null) {
      throw new FactoryMethodReturnsNullException(factory);
    }
    return instance;
  }

  private static <T> @Nullable T invoke(Invokable<?, ? extends T> factory, List<?> args)
      throws InvocationTargetException, IllegalAccessException {
    T returnValue = factory.invoke(null, args.toArray());
    if (returnValue == null) {

   * Future} fails with the given {@code exceptionType}, from the result provided by the {@code
   * fallback}. {@link Function#apply} is not invoked until the primary input has failed, so if the
   * primary input succeeds, it is never invoked. If, during the invocation of {@code fallback}, an
   * exception is thrown, this exception is used as the result of the output {@code Future}.
   *
   * <p>Usage example:

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.

    T instance = invoke(factory, args);
    if (instance == null) {
      throw new FactoryMethodReturnsNullException(factory);
    }
    return instance;
  }

  private static <T> @Nullable T invoke(Invokable<?, ? extends T> factory, List<?> args)
      throws InvocationTargetException, IllegalAccessException {
    T returnValue = factory.invoke(null, args.toArray());
    if (returnValue == null) {

   * connected - this does nothing and returns false. Otherwise, this returns true and the caller
   * should immediately invoke this method again until it returns false.
   *
   * This method may only be invoked by the writer thread. There may be only thread invoking this
   * method at a time.
   */
  @Throws(IOException::class)
  internal fun writeOneFrame(): Boolean {

    dispatcher: Dispatcher,
  ) {
  }

  /**
   * Invoked when [call] will be executed immediately.
   *
   * This method is invoked after [dispatcherQueueStart].
   */
  open fun dispatcherQueueEnd(
    call: Call,
    dispatcher: Dispatcher,
  ) {
  }

  /**
   * Invoked prior to a proxy selection.
   *
   * This will be invoked for route selection regardless of whether the client

  }

  /** Invoked when a binary (type `0x2`) message has been received. */
  open fun onMessage(
    webSocket: WebSocket,
    bytes: ByteString,
  ) {
  }

  /**
   * Invoked when the remote peer has indicated that no more incoming messages will be transmitted.
   */
  open fun onClosing(
    webSocket: WebSocket,
    code: Int,
    reason: String,
  ) {
  }

  /**

   * up, any time callers spend waiting for a thread may count toward their time limit, and in this
   * case the call may even time out before the target method is ever invoked.
   *
   * @param executor the ExecutorService that will execute the method calls on the target objects;
   *     for example, a {@link Executors#newCachedThreadPool()}.
   * @since 22.0
   */

 * </ul>
 *
 * <h3>Utility Classes</h3>
 * <ul>
 *   <li>{@link org.apache.maven.cling.invoker.mvnup.goals.StrategyOrchestrator} - Coordinates strategy execution</li>
 *   <li>{@link org.apache.maven.cling.invoker.mvnup.goals.PomDiscovery} - Discovers POM files in multi-module projects</li>

 * parameter whose declaration or type isn't annotated with an annotation with the simple name
 * {@code Nullable}, {@code CheckForNull}, {@code NullableType}, or {@code NullableDecl}.
 *
 * <p>The tested methods and constructors are invoked -- each time with one parameter being null and
 * the rest not null -- and the test fails if no expected exception is thrown. {@code
 * NullPointerTester} uses best effort to pick non-null default values for many common JDK and Guava