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

    if (graph instanceof TransposedGraph) {
      return ((TransposedGraph<N>) graph).graph;
    }

    return new TransposedGraph<>(graph);
  }

  /**
   * Returns a view of {@code graph} with the direction (if any) of every edge reversed. All other