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**To Reproduce**
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1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

**Expected behavior**
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import org.codelibs.fess.crawler.service.impl.UrlFilterServiceImpl;
import org.dbflute.utflute.core.PlainTestCase;

/**
 * Test class for UrlFilter interface.
 * Tests the contract and behavior of UrlFilter implementations.
 */
public class UrlFilterTest extends PlainTestCase {

    private UrlFilter urlFilter;
    private StandardCrawlerContainer container;

    @Override

**Describe the bug**
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**To Reproduce**
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1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

**Expected behavior**
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            this.destroyed = true;
        }

        public static void resetCounter() {
            instanceCounter.set(0);
        }
    }

    /**
     * Singleton test component for testing singleton behavior
     */
    public static class SingletonTestComponent {
        private static int instanceCount = 0;

        public SingletonTestComponent() {
            instanceCount++;
        }

import org.codelibs.fess.crawler.entity.ResponseData;
import org.codelibs.fess.crawler.processor.ResponseProcessor;
import org.dbflute.utflute.core.PlainTestCase;

/**
 * Test class for Rule interface.
 * Tests the contract and behavior of Rule implementations.
 */
public class RuleTest extends PlainTestCase {

    /**
     * Test implementation of Rule interface for testing purposes
     */
    public static class TestRule implements Rule {

 * Provides a common structure for handling delays at different stages of the crawling process.
 * It encapsulates the delay logic and exception handling, allowing subclasses to focus on
 * defining the specific delay behavior for each stage.
 *
 * <p>
 * This class defines the contract for delaying the crawling process at various points, such as:
 * </p>
 * <ul>
 *   <li>Before processing a URL ({@link #delayBeforeProcessing()})</li>

        // Final name should be from one of the threads
        assertNotNull(testTransformer.getName());
        assertTrue(testTransformer.getName().startsWith("thread"));
    }

    /**
     * Test inheritance behavior
     */
    public void test_inheritanceBehavior() {
        // Test that subclasses inherit name management
        TestTransformer transformer1 = new TestTransformer();

        assertEquals("changedId", registeredRule.getRuleId());
        assertSame(processor2, registeredRule.getResponseProcessor());
    }

    /**
     * Test inheritance behavior
     */
    public void test_inheritanceBehavior() {
        // Test that subclass can override match method
        ConditionalAbstractRule conditionalRule = new ConditionalAbstractRule();

        // Set null
        crawlerContext.setRobotsTxtUrlSet(null);
        assertNull(crawlerContext.getRobotsTxtUrlSet());
    }

    /**
     * Test LRU behavior of robotsTxtUrlSet
     */
    public void test_robotsTxtUrlSet_lru() {
        Set<String> urlSet = crawlerContext.getRobotsTxtUrlSet();

        // Add URLs up to capacity (10000)

 * It contains various attributes related to the crawler's state, configuration, and runtime data.
 * This class provides methods to access and modify these attributes, allowing for control and monitoring
 * of the crawler's behavior.
 *
 * <p>
 * The context includes information such as the session ID, active thread count, access count, crawler status,
 * URL filter, rule manager, interval controller, robots.txt URL set, sitemaps, number of threads,