// For discussion of <? extends Object>, see getAllPresent.
  void invalidateAll(Iterable<? extends Object> keys);

  /** Discards all entries in the cache. */
  void invalidateAll();

  /** Returns the approximate number of entries in this cache. */
  long size();

  /**
   * Returns a current snapshot of this cache's cumulative statistics, or a set of default values if

 *       to extract child URLs.</li>
 *   <li><b>defaultEncoding:</b> The default character encoding to use if none is
 *       specified in the HTML content.</li>
 *   <li><b>preloadSizeForCharset:</b> The number of bytes to read from the input
 *       stream to determine the character set encoding.</li>
 *   <li><b>invalidUrlPattern:</b> A regular expression pattern used to identify
 *       invalid URLs.</li>
 * </ul>
 *

Integrations and "plug-ins" can be built using the **Dependency Injection** system. But in fact, there is actually **no need to create "plug-ins"**, as by using dependencies it's possible to declare an infinite number of integrations and interactions that become available to your *path operation functions*.

    // user-specified -XX:+DisableExplicitGC.
    //
    // TODO(user): Consider using
    // java/lang/management/OperatingSystemMXBean.html#getSystemLoadAverage()
    //
    // TODO(user): Consider scaling by number of mutator threads,
    // e.g. using Thread#activeCount()
    return max(10L, Runtime.getRuntime().totalMemory() / (32L * 1024L * 1024L));
  }

  /**

         * This constructor parses the URL to extract bucket and object names.
         *
         * @param url The storage URL to connect to
         */
        protected StorageURLConnection(final URL url) {
            super(url);
            // Extract bucket name from host
            bucketName = url.getHost() != null ? url.getHost() : StringUtil.EMPTY;

        CrawlingParameterUtil.setUrlQueue(null);
        CrawlingParameterUtil.setCrawlerContext(null);
        CrawlingParameterUtil.setUrlQueueService(null);
        CrawlingParameterUtil.setDataService(null);
        super.tearDown();
    }

    // Helper method to create a simple mock UrlQueue
    private UrlQueue<?> createMockUrlQueue(final String sessionId, final String url) {
        return new UrlQueue<Object>() {
            @Override

        SimpleSession(
                MavenSession session,
                RepositorySystem repositorySystem,
                List<org.apache.maven.api.RemoteRepository> repositories) {
            super(session, repositorySystem, repositories, null, null, null);
        }

        @Override
        protected Session newSession(

 */
@GwtCompatible
public final class PercentEscaper extends UnicodeEscaper {

  // In some escapers spaces are escaped to '+'
  private static final char[] plusSign = {'+'};

  // Percent escapers output upper case hex digits (uri escapers require this).
  private static final char[] upperHexDigits = "0123456789ABCDEF".toCharArray();

  /** If true we should convert space to the {@code +} character. */

   *
   * @since 12.0
   */
  protected class StandardDescendingSet extends Sets.DescendingSet<E> {
    /** Constructor for use by subclasses. */
    public StandardDescendingSet() {
      super(ForwardingNavigableSet.this);
    }
  }

  @Override
  public Iterator<E> descendingIterator() {
    return delegate().descendingIterator();
  }

  @Override
  public NavigableSet<E> subSet(

                    boolean allowStubModel,
                    boolean recursive,
                    boolean processPlugins,
                    @Nullable List<RemoteRepository> repositories) {
                super(session, trace);
                this.path = path;
                this.source = source;
                this.allowStubModel = allowStubModel;
                this.recursive = recursive;