*
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
final class UndirectedNetworkConnections<N, E> extends AbstractUndirectedNetworkConnections<N, E> {

  UndirectedNetworkConnections(Map<E, N> incidentEdgeMap) {
    super(incidentEdgeMap);
  }

  static <N, E> UndirectedNetworkConnections<N, E> of() {