TF_Status* status) {
  NameRangeMap name_ranges;
  status->status =
      NameRangesForNode(oper->node, oper->node.op_def(), nullptr, &name_ranges);
  if (!status->status.ok()) return -1;
  auto iter = name_ranges.find(arg_name);
  if (iter == name_ranges.end()) {
    status->status = InvalidArgument("Output arg '", arg_name, "' not found");
    return -1;
  }

*   `tf.math`:

    *   Added `tf.math.approx_max_k` and `tf.math.approx_min_k` which are the
        optimized alternatives to `tf.math.top_k` on TPU. The performance
        difference ranges from 8 to 100 times depending on the size of k. When
        running on CPU and GPU, a non-optimized XLA kernel is used.

*   `tf.train`:

    *   Added `tf.train.TrackableView` which allows users to inspect the