@GwtCompatible
final class Absent<T> extends Optional<T> {
  static final Absent<Object> INSTANCE = new Absent<>();

  @SuppressWarnings("unchecked") // implementation is "fully variant"
  static <T> Optional<T> withType() {
    return (Optional<T>) INSTANCE;
  }

  private Absent() {}

  @Override
  public boolean isPresent() {
    return false;
  }

  @Override

    }

    @Test
    @DisplayName("Test getSize always returns 0")
    void testGetSize() {
        // Default instance
        assertEquals(0L, fileBasicInfo.getSize());

        // Instance with values
        FileBasicInfo info =
                new FileBasicInfo(TEST_CREATE_TIME, TEST_LAST_ACCESS_TIME, TEST_LAST_WRITE_TIME, TEST_CHANGE_TIME, TEST_ATTRIBUTES);

            throw new CrawlerSystemException("CrawlerClient instance is null. Cannot register null client.");
        }
        clientMap.put(Pattern.compile(regex), client);
    }

    /**
     * Adds a client with a regular expression pattern at a specific position.
     * @param regex The regular expression to match URLs.
     * @param client The CrawlerClient instance.
     * @param pos The position to add the client.
     */

  public <S extends Comparable<?>> Ordering<S> reverse() {
    return (Ordering<S>) ReverseNaturalOrdering.INSTANCE;
  }

  // preserving singleton-ness gives equals()/hashCode() for free
  private Object readResolve() {
    return INSTANCE;
  }

  @Override
  public String toString() {
    return "Ordering.natural()";
  }

  private NaturalOrdering() {}

<components namespace="fessCrawler">
    <component name="crawler" class="org.codelibs.fess.crawler.Crawler" instance="prototype"/>
    <component name="httpClient" class="org.codelibs.fess.crawler.client.http.HcHttpClient" instance="singleton"/>
    <component name="fileTransformer" class="org.codelibs.fess.crawler.transformer.impl.FileTransformer" instance="singleton"/>
</components>
```

### Crawler Context Configuration

```java

   * through java serialization. However, floating point rounding errors mean that it may be false
   * for some instances where the statistics are mathematically equal, including instances
   * constructed from the same values in a different order... or (in the general case) even in the
   * same order. (It is guaranteed to return true for instances constructed from the same values in

 * system. Custom scope annotations should be annotated with {@code @Scope}.
 * <p>
 * Built-in scopes include:
 * <ul>
 *   <li>{@link Singleton} - One instance per container</li>
 *   <li>{@link SessionScoped} - One instance per Maven session</li>
 *   <li>{@link MojoExecutionScoped} - One instance per plugin execution</li>
 * </ul>
 *
 * @see Singleton
 * @see SessionScoped
 * @see MojoExecutionScoped
 * @since 4.0.0
 */

        ProjectBuilderRequestBuilder() {}

        /**
         * Sets the Maven session for this request.
         *
         * @param session the Maven session
         * @return this builder instance
         */
        public ProjectBuilderRequestBuilder session(Session session) {
            this.session = session;
            return this;
        }

        /**

    protected DocumentBuilderFactoryUtil() {
    }

    /**
     * Returns a new instance of {@link DocumentBuilderFactory}.
     *
     * @return A new instance of {@link DocumentBuilderFactory}.
     */
    public static DocumentBuilderFactory newInstance() {
        return newInstance(false);
    }

    /**
     * Returns a new instance of {@link DocumentBuilderFactory}.
     *
     * @param external

  }

  private <T> T pickInstance(T[] instances, T defaultValue) {
    return pickInstance(Arrays.asList(instances), defaultValue);
  }

  private <T> T pickInstance(Collection<T> instances, T defaultValue) {
    if (instances.isEmpty()) {
      return defaultValue;
    }
    // generateInt() is 1-based.
    return Iterables.get(instances, (generateInt() - 1) % instances.size());
  }