}

    /** An empty array of {@link Traverser}. */
    protected static final Traverser[] EMPTY_ARRAY = new Traverser[0];

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

    /** Mapping from URL protocol (as key) to {@link TraverserFactory} (as value). */
    protected static final ConcurrentMap<String, TraverserFactory> traverserFactories = newConcurrentHashMap();
    static {

  /**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableBiMap} whose keys
   * and values are the result of applying the provided mapping functions to the input elements.
   * Entries appear in the result {@code ImmutableBiMap} in encounter order.
   *
   * <p>If the mapped keys or values contain duplicates (according to {@link

     * unmodifiable map with each of the entries. For example, {@code
     * Splitter.on(';').trimResults().withKeyValueSeparator("=>").split("a=>b ; c=>b")} will return
     * a mapping from {@code "a"} to {@code "b"} and {@code "c"} to {@code "b"}.
     *
     * <p>The returned map preserves the order of the entries from {@code sequence}.
     *

  }

  private TypeToken<?> resolveSupertype(Type type) {
    TypeToken<?> supertype = of(getCovariantTypeResolver().resolveType(type));
    // super types' type mapping is a subset of type mapping of this type.
    supertype.covariantTypeResolver = covariantTypeResolver;
    supertype.invariantTypeResolver = invariantTypeResolver;
    return supertype;
  }

  /**

     * unmodifiable map with each of the entries. For example, {@code
     * Splitter.on(';').trimResults().withKeyValueSeparator("=>").split("a=>b ; c=>b")} will return
     * a mapping from {@code "a"} to {@code "b"} and {@code "c"} to {@code "b"}.
     *
     * <p>The returned map preserves the order of the entries from {@code sequence}.
     *

    /**
     * Default constructor.
     */
    public NetworkExplorer() {
        super();
    }

    private static LogStream log = LogStream.getInstance();

    /** The MIME type mapping */
    private MimeMap mimeMap;
    /** The CSS style for HTML rendering */
    private String style;
    /** The NTLM SSP handler */
    private NtlmSsp ntlmSsp;
    /** Flag indicating if credentials were supplied */

    boolean isDfsDisabled();

    /**
     * Enable hack to make kerberos auth work with DFS sending short names
     *
     * This works by appending the domain name to the netbios short name and will fail horribly if this mapping is not
     * correct for your domain.
     *
     * Property {@code jcifs.smb.client.dfs.convertToFQDN} (boolean, default false)
     *
     * @return whether to convert NetBIOS names returned by DFS to FQDNs
     */

   * <p><b>{@code Stream} equivalent:</b> {@code
   * stream.collect(ImmutableMap.toImmutableMap(keyFunction, v -> v))}.
   *
   * @param keyFunction the function used to produce the key for each value
   * @return a map mapping the result of evaluating the function {@code keyFunction} on each value
   *     in this fluent iterable to that value
   * @throws IllegalArgumentException if {@code keyFunction} produces the same key for more than one

   * <p><b>{@code Stream} equivalent:</b> {@code
   * stream.collect(ImmutableMap.toImmutableMap(keyFunction, v -> v))}.
   *
   * @param keyFunction the function used to produce the key for each value
   * @return a map mapping the result of evaluating the function {@code keyFunction} on each value
   *     in this fluent iterable to that value
   * @throws IllegalArgumentException if {@code keyFunction} produces the same key for more than one

  /**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableBiMap} whose keys
   * and values are the result of applying the provided mapping functions to the input elements.
   * Entries appear in the result {@code ImmutableBiMap} in encounter order.
   *
   * <p>If the mapped keys or values contain duplicates (according to {@link