When is afterStateUpdated triggered for a repeater?

 Repeater::make('add_new_kids')
      ->schema([
         // Schema Fields go here
      ])->columnSpanFull()->columns(4)
      ->live()
      ->afterStateUpdated(function (Get $get) {
          $this->quantity = count($get('existing_kids') ?? []) + count($get('add_new_kids') ?? []);
          $this->subTotal = $this->quantity * $this->price;
      }),