* delayMillisBeforeProcessing parameter.
     *
     * @throws InterruptedRuntimeException if the thread is interrupted during the delay
     * @throws CrawlerSystemException if an error occurs while processing the URL
     */
    @Override
    protected void delayBeforeProcessing() {
        final UrlQueue<?> urlQueue = CrawlingParameterUtil.getUrlQueue();
        if (urlQueue == null) {

    }

    /**
     * Converts the input string to Katakana.
     * @param inputStr The input string.
     * @return The Katakana representation of the input string.
     * @throws IOException If an I/O error occurs.
     */
    protected String toKatakana(final String inputStr) throws IOException {
        final StringBuilder kanaBuf = new StringBuilder();

        final Reader rd = new StringReader(inputStr);

        // Handle successful response
        response.getItems().forEach(item -> 
            System.out.println("Async suggestion: " + item.getText()[0])
        );
    })
    .error(throwable -> {
        // Handle error
        System.err.println("Error: " + throwable.getMessage());
    });
```

## Advanced Usage

### Index from Existing Documents

```java

 * The rule checks if the URL matches the defined regex pattern and then validates the content as a sitemap.
 * If any exception occurs during the sitemap validation, it logs the error and returns false.
 *
 */
public class SitemapsRule extends RegexRule {
    /**
     * Serial version UID for serialization.
     */
    private static final long serialVersionUID = 1L;

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.crawler.exception;

/**
 * The class CrawlerSystemException is a runtime exception that is thrown when a system error occurs during crawling.
 * It extends the RuntimeException class and provides constructors for creating exceptions with a message, a cause, or both.

    /**
     * The HTTP status code for Not Found.
     */
    public static final int NOT_FOUND_STATUS_CODE = 404;

    /**
     * The HTTP status code for Server Error.
     */
    public static final int SERVER_ERROR_STATUS_CODE = 500;

    /**
     * A constant for no transformer.
     */
    public static final String NO_TRANSFORMER = "NONE";

    /**

     *
     * @param accessResultData the data containing the XML content to be parsed
     * @return a map containing the parsed data from the XML content
     * @throws CrawlerSystemException if an error occurs while parsing the XML content
     */
    public static Map<String, Object> getDataMap(final AccessResultData<?> accessResultData) {
        // create input source

     * @param item the SuggestItem containing the data to be indexed
     * @return a string representing the bulk line for OpenSearch indexing
     * @throws SuggesterException if an I/O error occurs during the creation of the bulk line
     */
    public static String createBulkLine(final String index, final String type, final SuggestItem item) {

     *
     * @param outputFile the converted output file
     * @param outExt the output file extension
     * @return the extracted text content
     * @throws ExtractException if an error occurs while reading the file
     */
    protected String getOutputContent(final File outputFile, final String outExt) {
        final Extractor extractor = getExtractor(outExt);
        if (extractor != null) {

    }

    /**
     * Returns an input stream from a deferred file output stream.
     *
     * @param dfos A deferred file output stream.
     * @return An input stream.
     * @throws IOException if an I/O error occurs.
     */
    protected InputStream getContentStream(final DeferredFileOutputStream dfos) throws IOException {
        if (dfos.isInMemory()) {
            return new ByteArrayInputStream(dfos.getData());
        }