*
   * @throws IllegalArgumentException if {@code edge} is not an element of this network
   */
  EndpointPair<N> incidentNodes(E edge);

  /**
   * Returns a live view of the edges which have an {@link #incidentNodes(Object) incident node} in
   * common with {@code edge}. An edge is not considered adjacent to itself.
   *

    }

    @Override
    public Set<E> outEdges(N node) {
      return delegate().inEdges(node); // transpose
    }

    @Override
    public EndpointPair<N> incidentNodes(E edge) {
      EndpointPair<N> endpointPair = delegate().incidentNodes(edge);
      return EndpointPair.of(network, endpointPair.nodeV(), endpointPair.nodeU()); // transpose
    }

    @Override
    public Set<E> edgesConnecting(N nodeU, N nodeV) {

    }

    @Override
    public Set<E> outEdges(N node) {
      return delegate().inEdges(node); // transpose
    }

    @Override
    public EndpointPair<N> incidentNodes(E edge) {
      EndpointPair<N> endpointPair = delegate().incidentNodes(edge);
      return EndpointPair.of(network, endpointPair.nodeV(), endpointPair.nodeU()); // transpose
    }

    @Override
    public Set<E> edgesConnecting(N nodeU, N nodeV) {