assertEquals("Duplicated authorities shall be filtered.", 2, map.size());
assertEquals("Duplicated authorities shall still exist.", 3, identifiers.size());
assertEquals("myID1", map.get(ID));
assertEquals("myUUID", map.get(UUID));
final Iterator<Citation> it = map.keySet().iterator();
assertTrue(it.hasNext());
assertSame(ID, it.next());
it.remove();
assertTrue(it.hasNext());
assertSame(UUID, it.next());