Exception cause = new RuntimeException("Image processing error");
        ThumbnailGenerationException exception = new ThumbnailGenerationException(message, cause);

        assertEquals(message, exception.getMessage());
        assertEquals(cause, exception.getCause());
        assertEquals("Image processing error", exception.getCause().getMessage());
    }

 * This callback processes file events (create, modify, delete) and manages document indexing and deletion
 * operations in the search engine. It supports recursive crawling with configurable depth and access count limits.
 *
 * <p>The implementation uses an executor service for concurrent processing of file operations and maintains

        assertNotNull(result);
        assertTrue(result.contains("3 docs")); // Verify the job executes
    }

    // Test handling of processing exception
    public void test_execute_withProcessingException() {
        // Create a mock that returns 0 to simulate processing error
        SearchEngineClient errorClient = new SearchEngineClient() {
            @Override
            public long updateByQuery(String index,

    String content = InputStreamUtil.getUTF8String(input);
}

// Resource traversal for processing multiple files
ResourceTraversalUtil.forEach("META-INF", (resource, is) -> {
    // Process each resource in the META-INF directory
    System.out.println("Processing: " + resource);
});
```

### Text Processing and JSON
```java
import org.codelibs.core.text.*;

// JSON utilities with proper escaping

     * @param localName the local name without prefix, or empty string if namespace processing is not performed
     * @param qName the qualified name with prefix, or empty string if qualified names are not available
     * @throws SAXException if a SAX error occurs during processing
     */
    @Override

import jakarta.annotation.PostConstruct;

/**
 * Helper class for document processing and manipulation in the Fess search system.
 * This class provides utilities for processing document content, titles, and digests,
 * handling text normalization, content extraction, and similar document hash encoding/decoding.
 * It also manages document processing requests and integrates with the crawler system.
 *
 */
public class DocumentHelper {

    @Resource
    protected LabelTypeHelper labelTypeHelper;

    /** Helper for query processing and transformation. */
    @Resource
    protected QueryHelper queryHelper;

    /** Configuration for query field mappings and processing. */
    @Resource
    protected QueryFieldConfig queryFieldConfig;

    /** Helper for role-based query filtering and security. */
    @Resource

    }

    public void test_constructor_withMessageAndCause() {
        // Test constructor with message and cause
        final String message = "Job processing failed";
        final Exception cause = new IllegalStateException("Invalid state");
        final JobProcessingException exception = new JobProcessingException(message, cause);

        assertNotNull(exception);

        }
        return Result.FAILED;
    }

    /**
     * Enumeration representing the possible results of thumbnail image processing.
     */
    protected enum Result {
        /** Thumbnail was successfully generated */
        OK,
        /** Thumbnail generation failed due to processing errors */
        FAILED,
        /** Image dimensions do not meet validation requirements */
        INVALID_SIZE,

     */
    public ThumbnailManager() {
        // Default constructor
    }

    /**
     * Initializes the thumbnail manager after construction.
     * Sets up base directory and starts background processing.
     */
    @PostConstruct
    public void init() {
        if (logger.isDebugEnabled()) {
            logger.debug("Initialize {}", this.getClass().getSimpleName());
        }