@Test
public void testRemove() throws Exception {

    // Removing one by one to check the index stays on track.
    toni.uuidKey.retract();
    assertEquals(eder, map.get(IndexKey.INDEX_ID).get(new Value(0)).iterator().next());
    assertEquals(michael, map.get(IndexKey.INDEX_ID).get(new Value(1)).iterator().next());
    eder.uuidKey.retract();
    Person next = map.get(IndexKey.INDEX_ID).get(new Value(0)).iterator().next();
    assertEquals(michael, next);
}