@Nullable V removeSuccessor(N node);

  /**
   * Add {@code node} as a predecessor to the origin node. In the case of an undirected graph, it
   * also becomes a successor. Associates {@code value} with the edge connecting the two nodes.
   */
  void addPredecessor(N node, V value);

  /**
   * Add {@code node} as a successor to the origin node. In the case of an undirected graph, it also

    this.supportsFastOffset = supportsFastOffset;
  }

  /**
   * Returns, conceptually, "origin + distance", or equivalently, the result of calling {@link
   * #next} on {@code origin} {@code distance} times.
   */
  C offset(C origin, long distance) {
    C current = origin;
    checkNonnegative(distance, "distance");
    for (long i = 0; i < distance; i++) {
      current = next(current);

        final String origin = httpRequest.getHeader("Origin");
        if (StringUtil.isNotBlank(origin)) {
            if (logger.isDebugEnabled()) {
                logger.debug("HTTP Request: {}", httpRequest.getMethod());
            }
            final CorsHandlerFactory factory = ComponentUtil.getCorsHandlerFactory();
            final CorsHandler handler = factory.get(origin);
            if (handler != null) {

import okhttp3.internal.authenticator.JavaNetAuthenticator

/**
 * Performs either **preemptive** authentication before connecting to a proxy server, or
 * **reactive** authentication after receiving a challenge from either an origin web server or proxy
 * server.
 *
 * ## Preemptive Authentication
 *
 * To make HTTPS calls using an HTTP proxy server OkHttp must first negotiate a connection with

     *     service is the origin of the stream. When zero, the origin is specified in the `origin`
     *     parameter.
     * @param origin when present, the [origin](http://tools.ietf.org/html/rfc6454) is typically
     *     represented as a combination of scheme, host and port. When empty, the origin is that of
     *     the `streamId`.

  Set<E> inEdges();

  Set<E> outEdges();

  /**
   * Returns the set of edges connecting the origin node to {@code node}. For networks without
   * parallel edges, this set cannot be of size greater than one.
   */
  Set<E> edgesConnecting(N node);

  /**
   * Returns the node that is adjacent to the origin node along {@code edge}.
   *
   * <p>In the directed case, {@code edge} is assumed to be an outgoing edge.
   */

   * returns an arbitrary (but consistent) endpoint of the origin edge.
   */
  public final N nodeU() {
    return nodeU;
  }

  /**
   * Returns the node {@link #adjacentNode(Object) adjacent} to {@link #nodeU()} along the origin
   * edge. If this {@link EndpointPair} {@link #isOrdered()}, this is equal to {@link #target()}.
   */
  public final N nodeV() {

 * @param <E> Edge parameter type
 */
abstract class AbstractDirectedNetworkConnections<N, E> implements NetworkConnections<N, E> {
  /** Keys are edges incoming to the origin node, values are the source node. */
  final Map<E, N> inEdgeMap;

  /** Keys are edges outgoing from the origin node, values are the target node. */
  final Map<E, N> outEdgeMap;

  private int selfLoopCount;

   * returns an arbitrary (but consistent) endpoint of the origin edge.
   */
  public final N nodeU() {
    return nodeU;
  }

  /**
   * Returns the node {@link #adjacentNode(Object) adjacent} to {@link #nodeU()} along the origin
   * edge. If this {@link EndpointPair} {@link #isOrdered()}, this is equal to {@link #target()}.
   */
  public final N nodeV() {

/**
 * The concrete route used by a connection to reach an abstract origin server. When creating a
 * connection the client has many options:
 *
 *  * **HTTP proxy:** a proxy server may be explicitly configured for the client. Otherwise, the
 *    [proxy selector][java.net.ProxySelector] is used. It may return multiple proxies to attempt.
 *  * **IP address:** whether connecting directly to an origin server or a proxy, opening a socket