DfsReferralDataInternal result = mockReferralData.combine(null);
            assertNotNull(result);

            // Test with concrete implementation - combine with null throws NPE
            assertThrows(NullPointerException.class, () -> concreteImplementation.combine(null));
        }

        @Test
        @DisplayName("Should handle null in append")
        void testAppendWithNull() {

import org.codelibs.fess.util.ComponentUtil;

public class WebFsIndexHelperTest extends UnitFessTestCase {

    private WebFsIndexHelper webFsIndexHelper;

    @Override
    public void setUp() throws Exception {
        super.setUp();
        webFsIndexHelper = new WebFsIndexHelper();
    }

    public void test_crawl_withNullParameters() {
        try {
            webFsIndexHelper.crawl("sessionId", null, null);

import org.codelibs.fess.util.ComponentUtil;

public class PermissionHelperTest extends UnitFessTestCase {

    public PermissionHelper permissionHelper;

    @Override
    public void setUp() throws Exception {
        super.setUp();
        permissionHelper = new PermissionHelper();
        permissionHelper.systemHelper = new SystemHelper();
    }

    public void test_encode() {

   * @param expectedSize the number of elements you expect to add to the returned set
   * @return a new, empty {@code CompactLinkedHashSet} with enough capacity to hold {@code
   *     expectedSize} elements without resizing
   * @throws IllegalArgumentException if {@code expectedSize} is negative
   */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> createWithExpectedSize(
      int expectedSize) {

        if (configId == null) {
            throw new FessSystemException("configId is null.");
        }
        if (configId.length() < 2) {
            throw new FessSystemException("Invalid configId: " + configId);
        }
        final CrawlingConfig config = crawlingConfigHelper.getCrawlingConfig(configId);
        if (config == null) {
            throw new FessSystemException("No crawlingConfig: " + configId);

    checkNotNull(callable);
    checkNotNull(executor);
    return submitAsync(
        new AsyncCallable<T>() {
          @Override
          public ListenableFuture<T> call() throws Exception {
            return immediateFuture(callable.call());
          }

          @Override
          public String toString() {
            return callable.toString();
          }
        },

   *
   * <p>TODO(kevinb): support concurrently modified collections?
   *
   * @param c the collection for which to return an array of elements
   * @param array the array in which to place the collection elements
   * @throws ArrayStoreException if the runtime type of the specified array is not a supertype of
   *     the runtime type of every element in the specified collection
   */

    extends AbstractTester<OneSizeTestContainerGenerator<C, E>> {
  protected SampleElements<E> samples;
  protected C container;

  @Override
  @OverridingMethodsMustInvokeSuper
  public void setUp() throws Exception {
    super.setUp();
    samples = this.getSubjectGenerator().samples();
    resetContainer();
  }

  /**
   * @return the contents of the container under test, for use by {@link #expectContents(Object[])

                    continue;
                }
                handler.processResource(entryName.substring(pos), new FilterInputStream(zipInputStream) {
                    @Override
                    public void close() throws IOException {
                        ZipInputStreamUtil.closeEntry(zipInputStream);
                    }
                });
            }
        }
    }

    /**

    private RelatedQueryHelper relatedQueryHelper;
    private MockRelatedQueryBhv mockBhv;
    private VirtualHostHelper virtualHostHelper;

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

        // Setup system properties for DI container
        File file = File.createTempFile("test", ".properties");
        file.deleteOnExit();