*
 * # SP base URL (must match Audience URI configured in Okta)
 * saml.sp.base.url=https://your-fess-server.example.com
 * </pre>
 *
 * <h2>Optional Configuration</h2>
 * <pre>
 * # User attribute mapping
 * saml.attribute.group.name=groups
 * saml.attribute.role.name=roles
 *
 * # Default groups/roles for authenticated users
 * saml.default.groups=user
 * saml.default.roles=user
 * </pre>
 *

    }

    /** 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

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

      "number_of_replicas": 0,
      "auto_expand_replicas": "${fess.index.auto_expand_replicas}"
    },
    "analysis": {
      "char_filter": {
        "mapping_fa_filter": {
          "type": "mapping",

      "number_of_replicas": 0,
      "auto_expand_replicas": "${fess.index.auto_expand_replicas}"
    },
    "analysis": {
      "char_filter": {
        "mapping_fa_filter": {
          "type": "mapping",

     * 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}.
     *

    tentativeArgs.set(i, alternateArg);
    return createInstance(factory, tentativeArgs).hashCode()
        == createInstance(factory, args).hashCode();
  }

  // distinctValues is a type-safe class-values mapping, but we don't have a type-safe data
  // structure to hold the mappings.
  @SuppressWarnings({"unchecked", "rawtypes"})
  private FreshValueGenerator newFreshValueGenerator() {
    FreshValueGenerator generator =

  }

  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}.
     *