import java.util.Properties;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;

/**
 * Test class for Config utility functionality
 */
@DisplayName("Config Utility Tests")
class ConfigTest extends BaseTest {

    private Properties testProperties;

    @BeforeEach
    void setUp() {
        testProperties = new Properties();

import static org.mockito.Mockito.when;

import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.mockito.Mock;

/**
 * Test class for DfsReferralData interface functionality
 */
@DisplayName("DfsReferralData Interface Tests")
class DfsReferralDataTest extends BaseTest {

    @Mock
    private DfsReferralData mockReferralData;

    @Test

import org.dbflute.optional.OptionalEntity;

import jakarta.annotation.Resource;

/**
 * Service class for managing duplicate host configuration CRUD operations.
 * This service provides functionality to create, read, update, and delete
 * duplicate host configurations used by the Fess crawler system.
 *
 * <p>Duplicate host configurations allow administrators to define hostname patterns

 * Classes implementing this interface can be discovered and loaded by Maven through the
 * Java ServiceLoader mechanism, allowing plugins and extensions to contribute functionality
 * to the Maven build process.
 * <p>
 * SPI services are typically registered in {@code META-INF/services/} files corresponding to
 * the specific service interface being implemented.
 * <p>

        assertNotNull(crawlerLogHelper);
    }

    public void test_log_method_exists() {
        // Test that the log method exists and can be called
        // We can't easily test the actual functionality without complex mocking
        // but we can verify the class structure
        assertNotNull(crawlerLogHelper);
        assertTrue(CrawlerLogHelper.class.getSuperclass().getSimpleName().contains("LogHelper"));
    }

    logger.error("Class not found: " + className, e);
}
```

## 🏗️ Architecture & Design Patterns

### Core Design Principles
CoreLib follows a **utility-class pattern** where most functionality is exposed through static methods:

- **Assertion-based validation** - All methods validate inputs using `AssertionUtil.assertArgumentNotNull()` and `AssertionUtil.assertArgumentNotEmpty()`

import org.opensearch.common.unit.TimeValue;

/**
 * Monitor target for tracking hot threads in the OpenSearch cluster.
 * This class extends MonitorTarget to provide monitoring functionality for
 * hot threads, which helps identify performance bottlenecks and resource
 * usage issues in the search engine cluster.
 */
public class HotThreadMonitorTarget extends MonitorTarget {

import jcifs.internal.util.SMBUtil;

/**
 * Base class for SMB1 NT Transaction response messages.
 *
 * NT Transactions are an extended form of the basic transaction protocol
 * that provides additional functionality for Windows NT-specific operations.
 */
public abstract class SmbComNtTransactionResponse extends SmbComTransactionResponse {

    private static final Logger log = LoggerFactory.getLogger(SmbComNtTransactionResponse.class);

 * specific language governing permissions and limitations
 * under the License.
 */

/**
 * Provides feature flag management and configuration capabilities for Maven core functionality.
 *
 * @since 4.0.0
 */

import org.dbflute.optional.OptionalEntity;

import jakarta.annotation.Resource;

/**
 * Service class for managing data configuration CRUD operations.
 * This service provides functionality to create, read, update, and delete
 * data configurations used by the Fess crawler system.
 *
 * <p>Data configurations define how the crawler should access and process