// on if we've decided that some of its consumers have to be declustered too.
  // Iterating the graph in post-order guarantees that consumers have been
  // visited before producers.
  std::vector<Node*> post_order;
  GetPostOrder(*graph, &post_order, /*stable_comparator=*/NodeComparatorName(),
               /*edge_filter=*/NotBackedge);

  absl::flat_hash_set<Node*> nodes_to_partially_decluster;
  TF_RETURN_IF_ERROR(

  std::vector<Node*> nodes_in_order;
  if (direction == Direction::kForward) {
    GetReversePostOrder(graph, &nodes_in_order,
                        /*stable_comparator=*/NodeComparatorName());
  } else {
    GetPostOrder(graph, &nodes_in_order,
                 /*stable_comparator=*/NodeComparatorName());
  }

  size_t old_result_size;
  int iterations = 0;

  const int kMaxIterations = 10 * 1000;