*   <li>Index update operations through callbacks</li>
     *   <li>Error handling and failure logging</li>
     *   <li>Cleanup of old documents after successful crawling</li>
     * </ul>
     */
    protected static class DataCrawlingThread extends Thread {

        /** Configuration for the data store being crawled */
        private final DataConfig dataConfig;

        /** Callback for handling document indexing operations */

	RoutePath    string
	TraceTo      *pubsub.PubSub[madmin.TraceInfo, madmin.TraceType]
	Dialer       ConnDialer
	// Sign a token for the given audience.
	AuthFn AuthFn
	// Callbacks to validate incoming connections.
	AuthToken ValidateTokenFn
}

// NewManager creates a new grid manager
func NewManager(ctx context.Context, o ManagerOptions) (*Manager, error) {
	found := false

				} else {
					clause.Expr{SQL: sql, Vars: vars}.Build(subdb.Statement)
				}
			} else {
				subdb.Statement.Vars = append(stmt.Vars, subdb.Statement.Vars...)
				subdb.callbacks.Query().Execute(subdb)
			}

			writer.WriteString(subdb.Statement.SQL.String())
			stmt.Vars = subdb.Statement.Vars
		default:
			switch rv := reflect.ValueOf(v); rv.Kind() {

/**
 * Base class for implementing services that can handle {@link #doStart} and {@link #doStop}
 * requests, responding to them with {@link #notifyStarted()} and {@link #notifyStopped()}
 * callbacks. Its subclasses must manage threads manually; consider {@link
 * AbstractExecutionThreadService} if you need only a single execution thread.
 *
 * @author Jesse Wilson
 * @author Luke Sandberg
 * @since 1.0
 */

  // threadpool, so that we avoid the possibility of running the runner_ in the
  // threadpool of GPU event mgr, as that can trigger more callbacks to be
  // scheduled on that same threadpool, causing a deadlock in cases where the
  // caller of event_mgr->ThenExecute() blocks on the completion of the callback
  // (as in the case of ConstOp kernel creation on GPU, which involves copying a
  // CPU tensor to GPU).

   *
   * @param future The future attach the callback to.
   * @param callback The callback to invoke when {@code future} is completed.
   * @param executor The executor to run {@code callback} when the future completes.
   * @since 10.0
   */
  public static <V extends @Nullable Object> void addCallback(
      ListenableFuture<V> future, FutureCallback<? super V> callback, Executor executor) {

  private val taskRunner = builder.taskRunner

  /** Asynchronously writes frames to the outgoing socket. */
  private val writerQueue = taskRunner.newQueue()

  /** Ensures push promise callbacks events are sent in order per stream. */
  private val pushQueue = taskRunner.newQueue()

  /** Notifies the listener of settings changes. */
  private val settingsListenerQueue = taskRunner.newQueue()

            }
            return v;
        };
    }

    private static UnaryOperator<String> or(UnaryOperator<String>... callbacks) {
        return s -> {
            for (UnaryOperator<String> cb : callbacks) {
                String r = cb.apply(s);
                if (r != null) {
                    return r;
                }
            }
            return null;

    scheduling. In your debugger you will see new thread names and more use of daemon threads.

 *  Fix: Don't drop callbacks on unexpected exceptions. When an interceptor throws an unchecked
    exception the callback is now notified that the call was canceled. The exception is still sent
    to the uncaught exception handler for reporting and recovery.

// required except where indicated.
typedef struct TFE_CustomDeviceTensorHandleMethods {
  int version = TFE_CUSTOM_DEVICE_VERSION;

  // Computes the rank of the tensor handle.
  //
  // Shapes are specified via callbacks because retrieving the shape of a tensor
  // is a blocking operation for async eager; custom devices should avoid
  // retrieving shapes of tensors they wrap until the custom device tensor's