* returns the expected data.
   *
   * @throws Throwable if the listener isn't called or if it resulted in a throwable or if the
   *     result doesn't match the expected value.
   */
  public void assertSuccess(Object expectedData) throws Throwable {
    // Verify that the listener executed in a reasonable amount of time.
    Assert.assertTrue(countDownLatch.await(1L, SECONDS));

        super(message);
    }

    public AbstractMojoExecutionException(String message, Throwable cause) {
        super(message, cause);
    }

    /**
     * Constructs a new {@code AbstractMojoExecutionException} exception wrapping an underlying {@code Throwable}.
     *
     * @param cause the cause which is saved for later retrieval by the {@link #getCause()} method.

  // have completed and we have processed them all.
  volatile @Nullable Set<Throwable> seenExceptionsField = null;

  volatile int remainingField;

  private static final AtomicHelper ATOMIC_HELPER;

  private static final LazyLogger log = new LazyLogger(AggregateFutureState.class);

  static {
    AtomicHelper helper;
    Throwable thrownReflectionFailure = null;
    try {
      helper = new SafeAtomicHelper();

    }
  }

  private static final class WrapperException extends Exception {
    WrapperException(Throwable t) {
      super(t);
    }
  }

  private static void rethrow(ExecutionException e) throws ExecutionException {
    Throwable wrapper = e.getCause();
    if (wrapper instanceof WrapperException) {
      Throwable cause = wrapper.getCause();
      if (cause instanceof RuntimeException) {

abstract class InterruptibleTask<T extends @Nullable Object> implements Runnable {

  @Override
  public void run() {
    T result = null;
    Throwable error = null;
    if (isDone()) {
      return;
    }
    try {
      result = runInterruptibly();
    } catch (Throwable t) {
      error = t;
    }
    if (error == null) {
      // The cast is safe because of the `run` and `error` checks.

        this(message, null, null);
    }

    public MetadataRetrievalException(Throwable cause) {
        this(null, cause, null);
    }

    public MetadataRetrievalException(String message, Throwable cause) {
        this(message, cause, null);
    }

    public MetadataRetrievalException(String message, Throwable cause, ArtifactMetadata artifact) {
        super(message, cause);

        this.artifact = artifact;

     * has failed.
     */
    final @Nullable Throwable failure;

    StateSnapshot(State internalState) {
      this(internalState, false, null);
    }

    StateSnapshot(
        State internalState, boolean shutdownWhenStartupFinishes, @Nullable Throwable failure) {
      checkArgument(
          !shutdownWhenStartupFinishes || internalState == STARTING,

    //
    @Override
    public void error(String msg) {
        out.print(ERROR);
        out.println(msg);
    }

    @Override
    public void error(String msg, Throwable t) {
        error(msg);

        if (null != t) {
            t.printStackTrace(out);
        }
    }

    //
    // Don't need any of this
    //
    @Override
    public String getName() {

  // & this future completes. Released when the future releases the reference to the running state
  private @Nullable Set<Throwable> seenExceptions = null;
  private int remaining;

  AggregateFutureState(int remainingFutures) {
    this.remaining = remainingFutures;
  }

  final Set<Throwable> getOrInitSeenExceptions() {
    if (seenExceptions == null) {
      seenExceptions = newHashSet();

    public MetadataGraphTransformationException(String message) {
        super(message);
    }

    public MetadataGraphTransformationException(Throwable cause) {
        super(cause);
    }

    public MetadataGraphTransformationException(String message, Throwable cause) {
        super(message, cause);
    }