});
        th.start();

        final CountDownLatch latch = new CountDownLatch(1);
        deferred.promise().then(response -> latch.countDown());
        assertTrue(latch.await(10, TimeUnit.SECONDS));
    }

    @Test
    public void test_doneAfterResolve() throws Exception {
        final Deferred<SuggestResponse> deferred = new Deferred<>();

        Thread th = new Thread(() -> {

});
```

## Troubleshooting

### Common Issues

#### Connection Timeouts
```java
// Increase timeout values
client.setConnectionTimeout(60000);  // 60 seconds
client.setSocketTimeout(120000);     // 120 seconds
```

#### Memory Issues
```java
// Reduce concurrent threads and batch sizes
crawler.crawlerContext.setNumOfThread(5);
crawler.crawlerContext.setMaxAccessCount(1000);
```

    /**
     * Gets the crawl delay value for the specified user agent from robots.txt.
     * The crawl delay specifies the time (in seconds) to wait between successive requests.
     *
     * @param userAgent The user agent string to match against robots.txt directives
     * @return The crawl delay value in seconds. Returns 0 if no matching directive is found
     *         or no crawl delay is specified for the matching directive.
     */

    /**
     * Cache for exclude filters.
     */
    protected LoadingCache<String, List<Pattern>> excludeFilterCache;

    /**
     * The expiration time for the filter cache in seconds.
     */
    protected int filterCacheExpireAfterWrite = 10; // 10sec

    /**
     * The maximum number of items to load into the cache.
     */
    protected int maxLoadSize = 10000;

    /**

    /** The maximum cached content size in bytes. Default is 1MB. */
    protected long maxCachedContentSize = 1024L * 1024L; // 1MB

    /** The access timeout in seconds. Default is null (no timeout). */
    protected Integer accessTimeout = null; // seconds

    /** The maximum content length in bytes. Default is null (no limit). */
    protected Long maxContentLength = null;

    /**

                        endLatch.countDown();
                    }
                }
            });
        }

        startLatch.countDown();
        endLatch.await(10, TimeUnit.SECONDS);
        executor.shutdown();

        assertEquals(0, errorCount.get());
        assertEquals("concurrentName", testTransformer.getName());
    }

    /**
     * Test concurrent name changes
     */

                        endLatch.countDown();
                    }
                }
            });
        }

        startLatch.countDown();
        endLatch.await(10, TimeUnit.SECONDS);
        executor.shutdown();

        assertEquals(threadCount * operationsPerThread, crawlerContext.getAccessCount());
    }

    /**
     * Test status getter and setter
     */

    private static final Logger logger = LogManager.getLogger(ApiExtractor.class);

    /** The URL of the API endpoint. */
    protected String url;

    /** The access timeout in seconds. */
    protected Integer accessTimeout; // sec

    /** The HTTP client used for API calls. */
    protected CloseableHttpClient httpClient;

    /** The connection timeout in milliseconds. */

    protected DnsResolver dnsResolver = new IdnDnsResolver();

    /** Map of authentication scheme providers */
    protected Map<String, AuthSchemeProvider> authSchemeProviderMap;

    /** Connection check interval in seconds */
    protected int connectionCheckInterval = 5; // sec

    /** Idle connection timeout in milliseconds */
    protected long idleConnectionTimeout = 60 * 1000L; // 1min

    /** Logger instance for this class. */
    private static final Logger logger = LogManager.getLogger(PdfExtractor.class);

    /** Timeout for PDF extraction in milliseconds (default: 30 seconds). */
    protected long timeout = 30000; // 30sec

    /** Whether the extraction thread should be a daemon thread. */
    protected boolean isDaemonThread = false;

    /**
     * Creates a new PdfExtractor instance.