* version of {@code com.google.common.base.Function} will be made to <i>extend</i> {@code
 * java.util.function.Function}, making conversion code necessary only in one direction. At that
 * time, this interface will be officially discouraged.
 *
 * @author Kevin Bourrillion
 * @since 2.0
 */
@GwtCompatible
public interface Function<F extends @Nullable Object, T extends @Nullable Object> {

import org.codelibs.fess.entity.FacetInfo;
import org.codelibs.fess.entity.GeoInfo;
import org.codelibs.fess.entity.HighlightInfo;
import org.codelibs.fess.entity.SearchRequestParams;
import org.codelibs.fess.mylasta.direction.FessConfig;
import org.codelibs.fess.util.ComponentUtil;
import org.lastaflute.web.util.LaRequestUtil;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

import jakarta.validation.constraints.Size;

 * future version of {@code com.google.common.base.Supplier} will be made to <i>extend</i> {@code
 * java.util.function.Supplier}, making conversion code necessary only in one direction. At that
 * time, this interface will be officially discouraged.
 *
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible
public interface Supplier<T extends @Nullable Object> {
  /**

    return ImmutableSet.copyOf(Traverser.forGraph(graph).breadthFirst(node));
  }

  // Graph mutation methods

  // Graph view methods

  /**
   * Returns a view of {@code graph} with the direction (if any) of every edge reversed. All other
   * properties remain intact, and further updates to {@code graph} will be reflected in the view.
   */
  public static <N> Graph<N> transpose(Graph<N> graph) {

public interface PredecessorsFunction<N> {

  /**
   * Returns all nodes in this graph adjacent to {@code node} which can be reached by traversing
   * {@code node}'s incoming edges <i>against</i> the direction (if any) of the edge.
   *
   * <p>Some algorithms that operate on a {@code PredecessorsFunction} may produce undesired results
   * if the returned {@link Iterable} contains duplicate elements. Implementations of such

public interface SuccessorsFunction<N> {

  /**
   * Returns all nodes in this graph adjacent to {@code node} which can be reached by traversing
   * {@code node}'s outgoing edges in the direction (if any) of the edge.
   *
   * <p>This is <i>not</i> the same as "all nodes reachable from {@code node} by following outgoing
   * edges". For that functionality, see {@link Graphs#reachableNodes(Graph, Object)}.
   *

   * @since 24.0
   */
  Set<E> incidentEdges(N node);

  /**
   * Returns a live view of all edges in this network which can be traversed in the direction (if
   * any) of the edge to end at {@code node}.
   *
   * <p>In a directed network, an incoming edge's {@link EndpointPair#target()} equals {@code node}.
   *

  @Override
  Set<N> adjacentNodes(N node);

  /**
   * Returns a live view of all nodes in this graph adjacent to {@code node} which can be reached by
   * traversing {@code node}'s incoming edges <i>against</i> the direction (if any) of the edge.
   *
   * <p>In an undirected graph, this is equivalent to {@link #adjacentNodes(Object)}.
   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}

  @Override
  Set<N> adjacentNodes(N node);

  /**
   * Returns a live view of all nodes in this graph adjacent to {@code node} which can be reached by
   * traversing {@code node}'s incoming edges <i>against</i> the direction (if any) of the edge.
   *
   * <p>In an undirected graph, this is equivalent to {@link #adjacentNodes(Object)}.
   *
   * <p>If {@code node} is removed from the graph after this method is called, the {@code Set}

| `FessUserLocaleProcessProvider` | `org.codelibs.fess.mylasta.direction.sponsor` | User locale detection |

## Language Detection and Selection

### User Interface Language

Fess determines the UI language in this order:

1. **Query parameter**: `?browser_lang=[locale]` (highest priority)
2. **Browser header**: `Accept-Language` header
3. **Fallback**: English (from `fess_label.properties` and `fess_message.properties`)