@Test
 public void testToString() {
   System.out.println(manager.toString());
   String expectNullValues =
       "Person [personID=0, CPR=null, fname=null,"
           + " lname=null, country=null, ZIP=null, city=null, address=null,"
           + " email=null, password=null]Staff [salary=0.0]Manager []";
   assertEquals(expectNullValues, manager.toString());
 }