public void ShiftDone() {
   state = State.idle;
   cashierGui.DoLeave();
   try {
     moving.acquire();
   } catch (InterruptedException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
   }
 }
 public void setGui(CashierGui gui) {
   cashierGui = gui;
   cashierGui.setPresent(true);
 }