auto cast_builder = NodeBuilder(cast_op_name, "Cast")
                          .Input(orig_const)
                          .Attr("DstT", DataTypeToEnum<DstT>::v());
  scope.UpdateBuilder(&cast_builder);
  Node* ret;
  scope.UpdateStatus(cast_builder.Finalize(scope.graph(), &ret));
  if (!scope.ok()) return Output();
  scope.UpdateStatus(scope.DoShapeInference(ret));
  return Output(ret, 0);
}

  const string unique_name = scope.GetUniqueNameForOp("Const");
  auto builder = NodeBuilder(unique_name, "Const")
                     .Attr("value", value)
                     .Attr("dtype", dtype);
  scope.UpdateBuilder(&builder);
  scope.UpdateStatus(builder.Finalize(graph, &ret));
  if (!scope.ok()) return Output();

  scope.UpdateStatus(scope.DoShapeInference(ret));
  if (!scope.ok()) return Output();

  return Output(ret);

  std::vector<NodeBuilder::NodeOut> input_list({enter_input, next_input});
  const string unique_name = scope.GetUniqueNameForOp("Merge");
  NodeBuilder builder = NodeBuilder(unique_name, "Merge").Input(input_list);
  scope.UpdateBuilder(&builder);

  Node* merge_node;
  TF_RETURN_IF_ERROR(builder.Finalize(scope.graph(), &merge_node));
  TF_RETURN_IF_ERROR(scope.DoShapeInference(merge_node));
  *merge_output = Output(merge_node, 0);