*/
    public RelatedContentHelper() {
        super();
    }

    private static final Logger logger = LogManager.getLogger(RelatedContentHelper.class);

    /**
     * Cache map storing related content configurations organized by virtual host key.
     * The outer map key is the virtual host key, and the value is a pair containing:
     * - First: Map of exact term matches (term -> content)

        throw new NullPointerException("at index " + i);
      }
      list.add(element);
    }
    equalityGroups.add(list);
    return this;
  }

  /** Run tests on equals method, throwing a failure on an invalid test */
  @CanIgnoreReturnValue
  public EqualsTester testEquals() {
    RelationshipTester<Object> delegate =
        new RelationshipTester<>(

  private final int startIndex;
  private final KnownOrder knownOrder;

  /**
   * Meta-exception thrown by {@link AbstractIteratorTester.MultiExceptionListIterator} instead of
   * throwing any particular exception type.
   */
  private abstract static class PermittedMetaException extends RuntimeException {
    static final PermittedMetaException UOE_OR_ISE =

    /**
     * Logger instance for this class.
     */
    protected static final Logger logger = LogManager.getLogger(ThumbnailManager.class);

    /**
     * Base directory for storing thumbnail files.
     */
    protected File baseDir;

    /**
     * List of available thumbnail generators.
     */
    protected final List<ThumbnailGenerator> generatorList = new ArrayList<>();

    /**

         * than a handful of exceptions. But it seems prudent to set a cap on how many we'll cache.
         * This avoids out-of-control memory consumption, and it keeps the cache from growing so
         * large that doing the lookup is noticeably slower than redoing the work would be.
         *
         * Ideally we'd have a real eviction policy, but until we see a problem in practice, I hope

    protected int maxErrorCount = 2;

    /** List of finished crawler session IDs for cleanup */
    protected List<String> finishedSessionIdList = new ArrayList<>();

    /** List of document boost matchers for scoring enhancement */
    private final List<DocBoostMatcher> docBoostMatcherList = new ArrayList<>();

    /** List of active crawler instances */
    private List<Crawler> crawlerList;

            fail("Expected NullPointerException");
        } catch (NullPointerException e) {
            // Expected
        }

        // equals with null input may return false instead of throwing NPE
        assertFalse(item3.equals(item1));
    }

    public void test_toString() {
        // Test toString method
        ProtwordsItem item = new ProtwordsItem(123, "testword");

     */
    protected class ProtwordsUpdater implements Closeable {

        /** Flag indicating if the update should be committed */
        protected boolean isCommit = false;

        /** Temporary file for storing updates */
        protected File newFile;

        /** Writer for writing to the temporary file */
        protected Writer writer;

        /** The item being updated */
        protected ProtwordsItem item;

        assertFalse(emptyOptional.isPresent());
        assertEquals("default", emptyOptional.orElse("default"));

        // Test that empty optional returns null instead of throwing
        assertNull(emptyOptional.orElse(null));
    }

    public void test_ofNullable_multipleTypesInSequence() {
        // Test multiple different types in sequence to ensure type safety

 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class RegularImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {
  @SuppressWarnings("unchecked") // TODO(cpovirk): Consider storing Entry<?, ?>[] instead.
  static final RegularImmutableBiMap<Object, Object> EMPTY =
      new RegularImmutableBiMap<>(
          null, null, (Entry<Object, Object>[]) ImmutableMap.EMPTY_ENTRY_ARRAY, 0, 0);