/**
  * Test if a {@link NullPointerException} is thrown by trying to delete a <code>null</code> {@link
  * Maintenance}
  */
 @Test(expected = NullPointerException.class)
 public void testDeleteNullMaintenance() {
   maintenanceDAO.deleteMaintenance(null);
 }
 /**
  * Test the deletion of an {@link Maintenance}. We check that the deleted {@link Maintenance}
  * can't be found.
  */
 @Test
 public void testDeleteMaintenance() {
   maintenanceDAO.deleteMaintenance(noneMaintenance);
   assertNull(maintenanceDAO.findById(noneMaintenanceId));
 }