ready.await()
    assertThat(dispatcher.runningCallsCount()).isEqualTo(2)
    assertThat(dispatcher.queuedCallsCount()).isEqualTo(0)
    assertThat(dispatcher.runningCalls())
      .containsExactlyInAnyOrder(a1, a2)
    assertThat(dispatcher.queuedCalls()).isEmpty()

    // Cancel some calls. That doesn't impact running or queued.
    a2.cancel()
    a3.cancel()

 * on single thread, keeping the listener logic simple. This listener also blocks on last transfer event to allow
 * output to perform possible cleanup. It spawns a daemon thread to consume queued events that may fall in even
 * concurrently.
 *
 * @since 4.0.0
 */
@Deprecated
public final class SimplexTransferListener extends AbstractTransferListener {

                queueSize.incrementAndGet();
            }
        }
        // If queue is full, let the buffer be garbage collected
    }

    /**
     * Get current cache statistics for monitoring
     * @return formatted statistics string
     */
    public static String getCacheStatistics() {
        return String.format("BufferCache: queued=%d, max=%d, utilization=%.1f%%", queueSize.get(), MAX_BUFFERS,

    /**
     * Used to update and read the latestTaskQueue field. Set to null once the runnable has been run
     * or queued.
     */
    @Nullable ExecutionSequencer sequencer;

    /**
     * Executor the task was set to run on. Set to null when the task has been queued, run, or
     * cancelled.
     */
    @Nullable Executor delegate;

    /**

### Replication of object version and metadata

 * on single thread, keeping the listener logic simple. This listener also blocks on last transfer event to allow
 * output to perform possible cleanup. It spawns a daemon thread to consume queued events that may fall in even
 * concurrently.
 *
 * @since 4.0.0
 */
public final class SimplexTransferListener extends AbstractTransferListener implements AutoCloseable {

      ReferenceQueue<Object> queue,
      PhantomReference<Object> frqReference) {
    this.queue = queue;

    this.finalizableReferenceClassReference = new WeakReference<>(finalizableReferenceClass);

    // Keep track of the FRQ that started us so we know when to stop.
    this.frqReference = frqReference;
  }

  /** Loops continuously, pulling references off the queue and cleaning them up. */

	}

	enc := json.NewEncoder(w)
	for {
		select {
		case ev := <-mergeCh:
			_, err := w.Write(ev)
			if err != nil {
				return
			}
			if len(mergeCh) == 0 {
				// Flush if nothing is queued
				xhttp.Flush(w)
			}
			grid.PutByteBuffer(ev)
		case <-emptyEventTicker:
			if err := enc.Encode(struct{ Records []event.Event }{}); err != nil {
				return
			}
			xhttp.Flush(w)

      ReferenceQueue<Object> queue,
      PhantomReference<Object> frqReference) {
    this.queue = queue;

    this.finalizableReferenceClassReference = new WeakReference<>(finalizableReferenceClass);

    // Keep track of the FRQ that started us so we know when to stop.
    this.frqReference = frqReference;
  }

  /** Loops continuously, pulling references off the queue and cleaning them up. */

    /**
     * QueueHolder holds the waiting and crawling queues.
     */
    protected static class QueueHolder {
        /**
         * Constructs a new QueueHolder.
         */
        public QueueHolder() {
            // Default constructor
        }

        /**
         * The queue for URLs waiting to be crawled.
         */
        protected Queue<OpenSearchUrlQueue> waitingQueue = new ConcurrentLinkedQueue<>();