@Test
 @DirtiesContext
 public void testSavePreference() {
   Preference pref = new Preference();
   pref.setEnabled(true);
   pref.setPushSenderID(1L);
   pref.setUsername("userA");
   try {
     getService().savePreference(pref);
   } catch (Exception e) {
     fail("Exception thrown when saveDevice tries to insert with null primary key.");
   }
   assertFalse("Preference saved without id and should not have.", null == pref.getId());
 }