protected static final int VALID_INPUT_DATA = 1;
  protected static final Exception EXCEPTION = new Exception("Test exception");

  protected SettableFuture<Integer> inputFuture;
  protected ListenableFuture<T> resultFuture;
  protected MockFutureListener listener;

  @Override
  protected void setUp() throws Exception {
    super.setUp();

    inputFuture = SettableFuture.create();

        // Then: Remove should throw UnsupportedOperationException
        UnsupportedOperationException exception = assertThrows(UnsupportedOperationException.class, iterator::remove);
        assertEquals("remove", exception.getMessage());
    }

    @Test
    @DisplayName("Close should be idempotent")
    void testClose_Idempotent() throws Exception {
        // Given: A valid iterator setup

    assertThat(Files.fileTraverser().breadthFirst(rootDir)).containsExactly(rootDir);
  }

  public void testFileTraverser_nonExistingFile() throws Exception {
    File file = new File(rootDir, "file-that-doesnt-exist");

    assertThat(Files.fileTraverser().breadthFirst(file)).containsExactly(file);
  }

  public void testFileTraverser_file() throws Exception {
    File file = newFile("some-file");

    assertThat(Files.fileTraverser().breadthFirst(rootDir)).containsExactly(rootDir);
  }

  public void testFileTraverser_nonExistingFile() throws Exception {
    File file = new File(rootDir, "file-that-doesnt-exist");

    assertThat(Files.fileTraverser().breadthFirst(file)).containsExactly(file);
  }

  public void testFileTraverser_file() throws Exception {
    File file = newFile("some-file");

import java.util.concurrent.atomic.AtomicReference;

import org.codelibs.fess.suggest.exception.SuggesterException;
import org.codelibs.fess.suggest.request.suggest.SuggestResponse;
import org.junit.Test;

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

        Thread th = new Thread(() -> {

        assertTrue(exception instanceof Throwable);
    }

    @Test
    public void test_serialization() {
        // Test that the exception has the correct serialVersionUID field
        ScriptEngineException exception = new ScriptEngineException("Serialization test");

        // Verify the exception can be created and basic properties work
        assertNotNull(exception);

  private static final ExecutorService executor = newFixedThreadPool(1);

  @Override
  protected void setUp() throws Exception {
    super.setUp();
    service = SimpleTimeLimiter.create(executor);
  }

  public void testNewProxy_goodMethodWithEnoughTime() throws Exception {
    SampleImpl target = new SampleImpl(DELAY_MS);
    Sample proxy = service.newProxy(target, Sample.class, ENOUGH_MS, MILLISECONDS);

     * and providing a <code>message</code>.
     *
     * @param message
     * @param cause
     */
    public MojoExecutionException(String message, Exception cause) {
        super(message, cause);
    }

    /**
     * Construct a new <code>MojoExecutionException</code> exception wrapping an underlying <code>Throwable</code>

        assertNull(exception.getMessage());
        assertNull(exception.getCause());
    }

    @Test
    public void test_constructor_withEmptyMessage() {
        // Test constructor with empty message
        String message = "";
        SearchEngineClientException exception = new SearchEngineClientException(message);

        assertNotNull(exception);
        assertEquals(message, exception.getMessage());

        try {
            dataIndexHelper.crawl("test-session");
            assertTrue("Should complete quickly with empty config list", true);
        } catch (Exception e) {
            assertTrue("Exception handling should be fast", true);
        }
    }

    @Test
    public void test_crawl_withConfigIdList_emptyList() {
        try {