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