*
 * <p>The DataIndexHelper supports:</p>
 * <ul>
 *   <li>Concurrent crawling of multiple data configurations</li>
 *   <li>Thread pool management for crawler execution</li>
 *   <li>Session-based crawling with cleanup operations</li>
 *   <li>Old document deletion after successful crawling</li>
 *   <li>Crawling execution monitoring and timing</li>
 * </ul>
 */
public class DataIndexHelper {

 *
 * <p>Features:
 * <ul>
 *   <li>Automatic delimiter detection (comma, tab, semicolon, pipe)</li>
 *   <li>Header row detection and extraction</li>
 *   <li>Column name to data value association</li>
 *   <li>Quoted field handling</li>
 *   <li>Column names as metadata</li>
 *   <li>Configurable encoding and row limits</li>
 * </ul>
 */
public class CsvExtractor extends AbstractExtractor {

 *   <li>connectTimeout - Connection timeout in milliseconds (default: 10000)</li>
 *   <li>readTimeout - Read timeout in milliseconds (default: 10000)</li>
 * </ul>
 *
 * <p>The client supports URLs in the format: {@code s3://bucket-name/object-path}
 *
 * <p>Features:
 * <ul>
 *   <li>Automatic initialization of AWS S3 client</li>
 *   <li>Support for HEAD and GET operations</li>
 *   <li>Content length validation</li>

 *   <li>writeTimeout - Write timeout in milliseconds (default: 10000)</li>
 *   <li>readTimeout - Read timeout in milliseconds (default: 10000)</li>
 * </ul>
 *
 * <p>The client supports URLs in the format: {@code gcs://bucket-name/object-path}
 *
 * <p>Features:
 * <ul>
 *   <li>Automatic initialization of GCS client</li>
 *   <li>Support for HEAD and GET operations</li>
 *   <li>Content length validation</li>

 * <ul>
 * <li>Retrieves crawled documents from the data service</li>
 * <li>Transforms document data using appropriate transformers</li>
 * <li>Applies document boosting rules and click/favorite count enhancements</li>
 * <li>Sends processed documents to the search engine for indexing</li>
 * <li>Manages cleanup of processed crawler session data</li>
 * </ul>
 *

 * </p>
 *
 * <p>
 * The class provides methods to:
 * </p>
 * <ul>
 *   <li>Initialize the client with SMB authentication details.</li>
 *   <li>Retrieve content and metadata from SMB files.</li>
 *   <li>Process access control entries to determine allowed and denied SIDs (Security Identifiers).</li>
 *   <li>Handle timeouts during SMB operations.</li>
 * </ul>
 *
 * <p>

 *
 * <p>
 * The handler relies on environment variables for configuration:
 * </p>
 * <ul>
 *   <li>{@code GCS_PROJECT_ID}: The Google Cloud project ID.</li>
 *   <li>{@code GCS_ENDPOINT}: Custom endpoint URL (optional, for testing with fake-gcs-server).</li>
 *   <li>{@code GCS_CREDENTIALS_FILE}: Path to service account JSON file (optional).</li>
 * </ul>
 *
 * <p>

 * </p>
 * <ul>
 *   <li>{@code S3_ENDPOINT}: The endpoint URL of the S3 service.</li>
 *   <li>{@code S3_ACCESS_KEY}: The access key for authentication.</li>
 *   <li>{@code S3_SECRET_KEY}: The secret key for authentication.</li>
 *   <li>{@code S3_REGION}: The region of the S3 service (default: us-east-1).</li>
 * </ul>
 *
 * <p>

 *
 * <p>Key features include:</p>
 * <ul>
 * <li>Incremental crawling support with last-modified timestamp checking</li>
 * <li>Document expiration handling</li>
 * <li>Child URL extraction and queueing</li>
 * <li>Integration with Fess configuration and permission systems</li>
 * <li>Client selection based on URL patterns</li>
 * </ul>
 *
 * @see CrawlerThread

 * </p>
 *
 * <p>
 * The class provides methods to:
 * </p>
 * <ul>
 *   <li>Initialize the client with SMB authentication details.</li>
 *   <li>Retrieve content and metadata from SMB files.</li>
 *   <li>Process access control entries to determine allowed and denied SIDs (Security Identifiers).</li>
 *   <li>Handle timeouts during SMB operations.</li>
 * </ul>
 *
 * <p>