int initCount = retrievedList.size();
assertTrue(retrievedList.contains(firstUser));
assertTrue(retrievedList.contains(secondUser));
retrievedList = db.deleteAll(firstUser);
User me1 = db.retrieve(User.class, "username", "bgaffey").toArray(arr)[0];
User me2 = db.retrieve(User.class, "username", "gafftron").toArray(arr)[0];
assertEquals(initCount, retrievedList.size());
assertEquals(me1, null);
assertEquals(me2, null);