while (!isFinished.get() && queue.isEmpty()) {
            addDocumentToQueue();
        }

        return queue.poll();
    }

    @Override
    public void close() {
        isFinished.set(true);
        queue.clear();
    }

    /**
     * Sets the scroll size.
     * @param scrollSize The scroll size.
     */
    public void setScrollSize(final int scrollSize) {

     *
     * @param responseData the response data to check
     * @return true if successful, false otherwise
     */
    protected boolean isSuccessful(final ResponseData responseData) {
        if (successfulHttpCodes == null) {
            return true;
        }
        final int httpStatusCode = responseData.getHttpStatusCode();
        for (final int code : successfulHttpCodes) {

                final Matcher matcher = pattern.matcher(url);
                if (matcher.matches()) {
                    match = true;
                }
            }
            if (match) {
                return false;
            }
        }

        return true;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.fess.crawler.filter.UrlFilter#processUrl(java.lang.String)

     * @return true if access is allowed, false if access is disallowed by robots.txt rules.
     *         Returns true if no matching directive is found for the user agent.
     */
    public boolean allows(final String path, final String userAgent) {
        final Directive directive = getMatchedDirective(userAgent);
        if (directive == null) {
            return true;
        }

        this.numberOfInputDocs = numberOfInputDocs;
        this.took = took;
        if (errors == null || errors.isEmpty()) {
            hasError = false;
        } else {
            hasError = true;
            errors.forEach(this.errors::add);
        }
    }

    /**
     * Returns the number of suggest documents.
     * @return The number of suggest documents.
     */

        return true;
    }

    @Override
    public void setUp() throws Exception {
        // create runner instance
        runner = new OpenSearchRunner();
        // create ES nodes
        final String clusterName = UUID.randomUUID().toString();
        runner.onBuild((number, settingsBuilder) -> {
            settingsBuilder.put("http.cors.enabled", true);

 * If {@link #ignoreException} is set to true, any exceptions thrown during the delay will be caught
 * and ignored. Otherwise, they will be re-thrown as {@link CrawlerSystemException}.
 * </p>
 *
 */
public abstract class AbstractIntervalController implements IntervalController {

    /**
     * Indicates whether exceptions during the delay process should be ignored.

        super(indexSettings, settings, name);
        ignoreCase = settings.getAsBoolean("ignore_case", true);
        n = settings.getAsInt("n", NGramSynonymTokenizer.DEFAULT_N_SIZE);
        delimiters = settings.get("delimiters", NGramSynonymTokenizer.DEFAULT_DELIMITERS);
        expand = settings.getAsBoolean("expand", true);

        settings.getAsBoolean("expand_ngram", false); // TODO remove

     * Returns whether SIDs (Security Identifiers) should be resolved.
     *
     * @return true if SIDs should be resolved, false otherwise
     */
    public boolean isResolveSids() {
        return resolveSids;
    }

    /**
     * Sets whether SIDs (Security Identifiers) should be resolved.
     *
     * @param resolveSids true to resolve SIDs, false otherwise
     */

Crawler crawler2 = container.getComponent("crawler");  
crawler2.setSessionId("session2");
crawler2.addUrl("https://site2.com");

// Execute concurrently
crawler1.setBackground(true);
crawler2.setBackground(true);

String sessionId1 = crawler1.execute();
String sessionId2 = crawler2.execute();

crawler1.awaitTermination();
crawler2.awaitTermination();
```

### Custom Interval Control