*
     * @return the user settings source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getUserSettingsSource();

    /**
     * The optional interpolation source used for interpolation.
     *
     * @return the interpolation source for interpolation
     */
    @Nonnull
    Optional<UnaryOperator<String>> getInterpolationSource();

    @Nonnull

 * be URL encoded if it contains reserved characters. According to RFC 2396
 * these characters are non US-ASCII characters and most meta characters
 * however jCIFS will work correctly with anything but '@' which is used
 * to delimit the userinfo component from the server and '%' which is the
 * URL escape character itself.
 * <p>
 * The server
 * component may a traditional NetBIOS name, a DNS name, or IP

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

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

    /** Configuration key for crawler clients used in parameter maps */
    protected static final String CRAWLER_CLIENTS = "crawlerClients";

    /**
     * Cache for client rules mapping client names to their corresponding URL patterns.

    try {
      if (future.isCancelled()) {
        // Clear futures prior to cancelling children. This sets our own state but lets
        // the input futures keep running, as some of them may be used elsewhere.
        futures = null;
        cancel(false);
      } else {
        collectValueFromNonCancelledFuture(index, future);
      }
    } finally {
      /*

type endpointSet struct {
	argPatterns []ellipses.ArgPattern
	endpoints   []string   // Endpoints saved from previous GetEndpoints().
	setIndexes  [][]uint64 // All the sets.
}

// Supported set sizes this is used to find the optimal
// single set size.
var setSizes = []uint64{2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}

// getDivisibleSize - returns a greatest common divisor of
// all the ellipses sizes.

   * are iterated in the order they were encountered. If two values for the same key are {@linkplain
   * Object#equals equal}, the first value encountered is used.
   *
   * @throws NullPointerException if any key, value, or entry is null
   * @since 19.0
   */
  public static <K, V> ImmutableSetMultimap<K, V> copyOf(

// The sparse map is stored in the tar header if it's small enough.
// If it's larger than four entries, then one or more extension headers are used
// to store the rest of the sparse map.
//
// The Header.Size does not reflect the size of any extended headers used.
// Thus, this function will read from the raw io.Reader to fetch extra headers.
// This method mutates blk in the process.

   * and duplex calls where the timeout only applies to the initial setup.
   */
  fun timeoutEarlyExit() {
    check(!timeoutEarlyExit)
    timeoutEarlyExit = true
    timeout.exit()
  }

  /**
   * @param closeExchange true if the current exchange should be closed because it will not be used.

   *     .add("y", null)
   *     .toString();
   * }
   *
   * <p>Note that in GWT, class names are often obfuscated.
   *
   * @param self the object to generate the string for (typically {@code this}), used only for its
   *     class name
   * @since 18.0 (since 2.0 as {@code Objects.toStringHelper()}).
   */
  public static ToStringHelper toStringHelper(Object self) {

5. Copy the `./app` directory inside the `/code` directory.

    As this has all the code which is what **changes most frequently** the Docker **cache** won't be used for this or any **following steps** easily.

    So, it's important to put this **near the end** of the `Dockerfile`, to optimize the container image build times.