// control dependencies are not to be executed. For single output nodes,
  // Placeholders can be converted to a NoOp if there are no uses, and
  // PlaceholderWithDefault can be converted to an Identity.
  for (const auto* edge : control_edges) {
    graph_->AddControlEdge(placeholder_node, edge->dst());
    graph_->RemoveControlEdge(edge);
  }

  if (update_inplace) {