OnPlayerEnter(Agent : agent) : void =
    if (not DoorIsOpen?):
        # If the door is closed, open it.
        set DoorIsOpen = true
        door_mover.MoveToEnd()
        # Play a beep sound here!
        # e.g. open_sound.Play() where open_sound is an
        # @editable customizable_audio_player_device
    else:
        # The door is already open — nothing extra to do.
        false

OnPlayerExit(Agent : agent) : void =
    if (DoorIsOpen?):
        # If the door is open, close it.
        set DoorIsOpen = false
        door_mover.MoveToBegin()
        # Play a whoosh sound here!
        # e.g. close_sound.Play() where close_sound is an
        # @editable customizable_audio_player_device
    else:
        # The door is already closed — nothing extra to do.
        false