/** Array of supported file protocols for URL classification. */
    protected String[] fileProtocols = { "file:", "smb:", "smb1:", "ftp:", "storage:" };

    /** Queue to track the current XML element hierarchy during parsing. */
    protected LinkedList<String> tagQueue;

    /** List to store parsed label types for access control. */
    protected List<LabelType> labelList;

 */
package org.apache.maven.model.validation;

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;

import java.io.File;
import java.util.Arrays;
import java.util.Deque;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;

  Now, when unschedulable Pods are updated, the scheduling queue checks with QueueingHint(s) whether the update may make the pods schedulable, and requeues them to activeQ/backoffQ **only when** at least one QueueingHint(s) return Queue. 
  
  Action required for custom scheduler plugin developers:

	bucketNotificationBuf := `<NotificationConfiguration><QueueConfiguration><Event>s3:ObjectCreated:Put</Event><Filter><S3Key><FilterRule><Name>prefix</Name><Value>images/</Value></FilterRule></S3Key></Filter><Id>1</Id><Queue>arn:minio:sqs:us-east-1:444455556666:webhook</Queue></QueueConfiguration></NotificationConfiguration>`
	// generate a random bucket Name.
	bucketName := getRandomBucketName()
	// HTTP request to create the bucket.

 * rate limit itself.
 *
 * {@snippet :
 * class CrawlingService extends AbstractScheduledService {
 *   private Set<Uri> visited;
 *   private Queue<Uri> toCrawl;
 *   protected void startUp() throws Exception {
 *     toCrawl = readStartingUris();
 *   }
 *
 *   protected void runOneIteration() throws Exception {
 *     Uri uri = toCrawl.remove();

    }
}
```

## 9. Performance and Optimization

### 9.1 Witness Event Batching
```java
public class WitnessEventBatcher {
    private final Queue<WitnessNotification> pendingNotifications;
    private final ScheduledExecutorService scheduler;
    private final int batchSize = 10;
    private final long batchTimeout = 100;  // 100ms
    

			}
			t.Log("Client Context canceled. err state:", err)
			clientCanceled <- time.Now()
		}(t)
		start := time.Now()
		if st.Requests != nil {
			defer close(st.Requests)
		}
		// Fill up queue.
		for sendReq {
			select {
			case st.Requests <- []byte("Hello"):
				time.Sleep(10 * time.Millisecond)
			default:
				sendReq = false
			}
		}
		cancel()
		<-serverCanceled

- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.

public abstract interface class okhttp3/Call : java/lang/Cloneable {
	public abstract fun addEventListener (Lokhttp3/EventListener;)V
	public abstract fun cancel ()V
	public abstract fun clone ()Lokhttp3/Call;
	public abstract fun enqueue (Lokhttp3/Callback;)V
	public abstract fun execute ()Lokhttp3/Response;
	public abstract fun isCanceled ()Z
	public abstract fun isExecuted ()Z
	public abstract fun request ()Lokhttp3/Request;

- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.