*/
  public static <N> Traverser<N> forGraph(SuccessorsFunction<N> graph) {
    return new Traverser<N>(graph) {
      @Override
      Traversal<N> newTraversal() {
        return Traversal.inGraph(graph);
      }
    };
  }

  /**
   * Creates a new traverser for a directed acyclic graph that has at most one path from the start