*
   * <ol>
   *   <li>calls {@link ExecutorService#shutdown()}, disabling acceptance of new submitted tasks.
   *   <li>awaits executor service termination for half of the specified timeout.
   *   <li>if the timeout expires, it calls {@link ExecutorService#shutdownNow()}, cancelling
   *       pending tasks and interrupting running tasks.
   *   <li>awaits executor service termination for the other half of the specified timeout.
   * </ol>
   *

    /** The key of the configuration. e.g. config_id */
    String INDEX_FIELD_config_id = "index.field.config_id";

    /** The key of the configuration. e.g. expires */
    String INDEX_FIELD_EXPIRES = "index.field.expires";

    /** The key of the configuration. e.g. url */
    String INDEX_FIELD_URL = "index.field.url";

    /** The key of the configuration. e.g. doc_id */

     * This method is called automatically after the bean construction is complete.
     * The cache is configured with a maximum size of 100 entries and expires after 10 minutes.
     */
    @PostConstruct
    public void init() {
        if (logger.isDebugEnabled()) {
            logger.debug("Initializing {}", this.getClass().getSimpleName());
        }

var supportedHeaders = []string{
	"content-type",
	"cache-control",
	"content-language",
	"content-encoding",
	"content-disposition",
	"x-amz-storage-class",
	xhttp.AmzStorageClass,
	xhttp.AmzObjectTagging,
	"expires",
	xhttp.AmzBucketReplicationStatus,
	"X-Minio-Replication-Server-Side-Encryption-Sealed-Key",
	"X-Minio-Replication-Server-Side-Encryption-Seal-Algorithm",
	"X-Minio-Replication-Server-Side-Encryption-Iv",

    protected String loggerName = "fess.log.crawler.stats";

    /** Maximum number of statistics objects to cache. */
    protected long maxCacheSize = 1000;

    /** Time in milliseconds after which cache entries expire after write. */
    protected long cacheExpireAfterWrite = 10 * 60 * 1000L;

    /** Cache for storing statistics objects keyed by crawler object identifiers. */
    protected LoadingCache<String, StatsObject> statsCache;

				objectsFailed = float64(mj.KeyRotate.ObjectsFailed)
				bucket = mj.KeyRotate.Bucket
			case madmin.BatchJobExpire:
				objects = float64(mj.Expired.Objects)
				objectsFailed = float64(mj.Expired.ObjectsFailed)
				bucket = mj.Expired.Bucket
			}
			metrics = append(metrics,
				MetricV2{
					Description: MetricDescription{
						Namespace: bucketMetricNamespace,
						Subsystem: "batch",

    }
}
```

## 9. Performance Considerations

### 9.1 Memory Management
- Lease entries should be evicted based on LRU when max leases reached
- Implement periodic cleanup of expired leases

### 9.2 Thread Safety
- Use concurrent data structures for lease storage
- Minimize lock contention in hot paths
- Async handling of lease breaks

### 9.3 Network Efficiency

        // cid
        final String configId = crawlingConfig.getConfigId();
        if (configId != null) {
            putResultDataBody(dataMap, fessConfig.getIndexFieldConfigId(), configId);
        }
        //  expires
        if (documentExpires != null) {
            putResultDataBody(dataMap, fessConfig.getIndexFieldExpires(), documentExpires);
        }
        // segment

        response.header("Pragma", "no-cache");
        response.header("Cache-Control", "no-cache");
        response.header("Expires", "Thu, 01 Dec 1994 16:00:00 GMT");
        response.contentTypeOctetStream();
        return response.stream(out -> {
            try {
                downloadObject(getObjectName(pi.getPath(), pi.getName()), out);

	// TransitionVersionID stores a version ID of the object associate
	// with the remote tier.
	TransitionVersionID string `msg:"tv"`
	// ExpireRestored indicates that the restored object is to be expired.
	ExpireRestored bool `msg:"exp"`

	// DataDir of the file
	DataDir string `msg:"dd"`

	// Indicates if this object is still in V1 format.
	XLV1 bool `msg:"v1"`