{
    GraphDefBuilder builder(GraphDefBuilder::kFailImmediately);
    Node* a =
        ops::SourceOp("UncompilableNullary", builder.opts().WithName("A"));

    // Builds a Symbolic gradient for Supported
    NodeBuilder b_builder("B", "SymbolicGradient",
                          builder.opts().op_registry());
    NameAttrList b_name_attr;
    b_name_attr.set_name("Supported");
    b_builder.Attr("f", b_name_attr);

  // Don't set any value field in the proto, since it is only going to be used
  // for shape inference.

  GraphDefBuilder::Options options(graph_out, /*status=*/nullptr);
  NodeBuilder node_builder(options.GetNameForOp("KnownShape"), "Const",
                           options.op_registry());
  node_builder.Attr("dtype", data_type).Attr("value", dummy_proto);

  if (!scope.ok()) return;
  auto _output_index = ops::AsNodeOut(scope, output_index);
  if (!scope.ok()) return;
  Node* ret;
  const auto unique_name = scope.GetUniqueNameForOp("_SwitchN");
  auto builder = NodeBuilder(unique_name, "_SwitchN")
                     .Input(_data)
                     .Input(_output_index)
                     .Attr("num_outs", num_outs);
  scope.UpdateBuilder(&builder);