4. **Async Support**: Both synchronous (`executeSync()`) and asynchronous (`execute()`) execution modes

## Technical Details

- **Java Version**: 17+
- **Dependencies**:
  - Apache Commons IO 2.19.0 (runtime)
  - JUnit 4.13.2 (test)
- **Module Name**: `org.codelibs.curl4j`
- **Package Structure**: `org.codelibs.curl.*`
- **Build Tool**: Maven 3.x
- **Test Coverage**: JaCoCo plugin enabled

## Code Style

import java.util.Deque;
import java.util.Map;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicInteger;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit tests for {@link CacheLoader}.
 *
 * @author Charles Fry
 */
@NullUnmarked
public class CacheLoaderTest extends TestCase {

import org.apache.maven.cling.invoker.mvnup.UpgradeContext;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.Arguments;
import org.junit.jupiter.params.provider.MethodSource;

import static org.junit.jupiter.api.Assertions.assertEquals;

import org.apache.maven.settings.building.SettingsProblemCollector;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;

/**
 */
class DefaultSettingsValidatorTest {

package jcifs.internal.dtyp;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

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

/**
 * Test class for SecurityInfo interface constants
 */

package jcifs.smb1.smb1;

import static jcifs.smb1.smb1.ServerMessageBlock.SMB_COM_WRITE;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.lang.reflect.Field;

import org.junit.jupiter.api.Test;

/**
 * Tests for SmbComWrite command - SMB write operations
 */
public class SmbComWriteTest {

package jcifs.dcerpc.ndr;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;
import static org.mockito.Mockito.when;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

class NdrSmallTest {

    @Mock

import java.util.Iterator;
import org.junit.Ignore;

/**
 * Tester for {@code BiMap.remove}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Common parent class for {@link ListIndexOfTester} and {@link ListLastIndexOfTester}.
 *
 * @author Chris Povirk
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.Mockito.when;

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