@Override
    public AlarmId id() {
        return id;
    }
@Test
    public void testId() {
        final DefaultAlarm a = generate();
        final DefaultAlarm b = new DefaultAlarm.Builder(a).build();

        assertEquals("id ignored in equals", a, b);
        assertEquals(ALARM_ID, a.id());
        assertEquals(ALARM_ID, b.id());
        assertEquals(ALARM_ENTITY_ID, b.source());

    }