return
	}

	// flow adds an edge from vertex src representing that typ flows to tpar.
	flow := func(src int, typ Type) {
		weight := 1
		if typ == targ {
			weight = 0
		}

		w.addEdge(w.typeParamVertex(tpar), src, weight, pos, targ)
	}

	// Recursively walk the type argument to find any defined types or
	// type parameters.
	var do func(typ Type)
	do = func(typ Type) {

    public Collection<Vertex> getVertices() {
        return vertices.values();
    }

    Vertex addVertex(String label) {
        return vertices.computeIfAbsent(label, Vertex::new);
    }

    void addEdge(Vertex from, Vertex to) throws CycleDetectedException {
        from.children.add(to);
        to.parents.add(from);
        List<String> cycle = findCycle(to);
        if (cycle != null) {

import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;

class Graph {

    final Map<String, Set<String>> graph = new LinkedHashMap<>();

    synchronized void addEdge(String from, String to) throws CycleDetectedException {
        if (graph.computeIfAbsent(from, l -> new HashSet<>()).add(to)) {

    public Collection<Vertex> getVertices() {
        return vertices.values();
    }

    Vertex addVertex(String label) {
        return vertices.computeIfAbsent(label, Vertex::new);
    }

    void addEdge(Vertex from, Vertex to) throws CycleDetectedException {
        from.children.add(to);
        to.parents.add(from);
        List<String> cycle = findCycle(to);
        if (cycle != null) {

                                                              : args[i].type)
            .Attr("index", i)
            .Finalize(graph.get(), &node);
    TF_RETURN_IF_ERROR(status);
    graph->AddEdge(node, 0, main_node, i);
  }

  // Similarly with return values, create dummy _Retval nodes fed by `node`.
  for (int64_t i = 0, end = result_types.size(); i < end; ++i) {
    Node* node;

                    MetadataGraphVertex newV = res.addVertex(newMd);
                    MetadataGraphVertex sourceV = res.addVertex(edge.getSource().getMd());

                    res.addEdge(sourceV, newV, edge);
                }
            }
            // System.err.println("Original graph("+graph.getVertices().size()+"):\n"+graph.toString());

  // Create the backedges from the NextIteration nodes to the Merge nodes.
  for (size_t i = 0; i < num_loop_vars; ++i) {
    const int merge_backedge_output_index = 1;
    scope.graph()->AddEdge(next_outputs[i].node(), next_outputs[i].index(),
                           merge_outputs[i].node(),
                           merge_backedge_output_index);
  }

  outputs->resize(num_loop_vars);

	if err != nil {
		log.Fatal(err)
	}

	var out []byte
	if *flagDot {
		var b bytes.Buffer
		g.TransitiveReduction()
		// Add cyclic edges for visualization.
		for k := range cyclicRanks {
			g.AddEdge(k, k)
		}
		// Reverse the graph. It's much easier to read this as
		// a "<" partial order than a ">" partial order. This
		// ways, locks are acquired from the top going down