Do I need to write my own PID controller when using ros2_control?

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Hi all, while using forward_controller in ros2_control I found:

There is no PID control code involved in ros2_control_demo. I think this is because ros2_control_demo is built on virtual hardware, for example, it handles the relationship between hw_state and hw_command like this:

hardware_interface::return_type RRBotSystemPositionOnlyHardware::read()
{
  RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Reading...");

  for (uint i = 0; i < hw_states_.size(); i++)
  {
    // Simulate RRBot's movement
    hw_states_[i] = hw_states_[i] + (hw_commands_[i] - hw_states_[i]) / hw_slowdown_;
    RCLCPP_INFO(
      rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Got state %.5f for joint %d!",
      hw_states_[i], i);
  }
  RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Joints successfully read!");

  return hardware_interface::return_type::OK;
}

Does that mean I need to write my own PID control code if using real hardware?