Didnt understand how parent state works

edit

autoware_states_vehicle: - First, thank you so much for the open-source driving software. I was going through this repo for studying the state machines that have been designed. I looked at the attached picture here. I didn't understand what parent state represents here? According to the picture, the LocalizationInit state is the target for SensorInit so for LocalizationInit the parent could be SensorInit, how do we relate it to directly Init State. Could anyone please help me to understand this?

    StateName: Start
    Transition:
      -
        Key: started
        Target: Init
    Parent: ~
  -
    StateName: Init
    Transition:
      -
        Key: init_start
        Target: SensorInit
    Parent: ~
  -
    StateName: SensorInit
    Transition:
      -
        Key: sensor_is_ready
        Target: LocalizationInit
    Parent: Init
  -
    StateName: LocalizationInit
    Transition:
      -
        Key: localization_is_ready
        Target: PlanningInit
    Parent: Init
  -
    StateName: PlanningInit
    Transition:
      -
        Key: planning_is_ready
        Target: VehicleInit
    Parent: Init