const Node* switch_node = (*it)->src();

  // Check if the Switch is driven by LoopCond.
  const Node* maybe_loop_cond;
  TF_RETURN_IF_ERROR(switch_node->input_node(1, &maybe_loop_cond));
  if (!maybe_loop_cond->IsLoopCond()) {
    return false;
  }

  // Check if the Identity is driving any const nodes through a control edge.
  bool driving_any_consts =
      absl::c_any_of(node->out_edges(), [](const Edge* e) {

            loc, operands[0].getType(), result.attributes);
    return builder_.create<mlir::tf_executor::NextIterationSinkOp>(
        loc, source_op.getToken(), operands, result.attributes);
  }
  if (node.IsLoopCond()) {
    return builder_.create<mlir::tf_executor::LoopCondOp>(loc, types, operands,
                                                          result.attributes);
  }
  if (node.IsEnter()) {