// Move regions to the new op.
  for (auto it : llvm::zip(op_->getRegions(), new_op->getRegions())) {
    Region& old_region = std::get<0>(it);
    Region& new_region = std::get<1>(it);
    new_region.takeBody(old_region);
  }

  // Insert stores to all written resources.
  for (Value resource : written_resources_) {
    ResourceInfo& info = resources_[resource];

  auto ctrl_op = op_builder.create<mlir::TFL::ControlNodeOp>(
      op_loc, cloned_op->getResultTypes(),
      mlir::TFL::ControlType::get(op->getContext()), control_tokens);
  ctrl_op.getBody().takeBody(region);

  // Store the control_token output for use by downstream nodes.
  maybe_control_node->second.outgoing = ctrl_op.getControl();

  // Remove the original op.