if (!network.isDirected()) {
      return network; // the transpose of an undirected network is an identical network
    }

    if (network instanceof TransposedNetwork) {
      return ((TransposedNetwork<N, E>) network).network;
    }

    return new TransposedNetwork<>(network);
  }

  static <N> EndpointPair<N> transpose(EndpointPair<N> endpoints) {
    if (endpoints.isOrdered()) {