for (int i=4;i<10000;i++) {
sm = (PersistentStructMap<String, Integer>) sm.assoc(i+"", i);
}
List<Map.Entry<String, Integer>> l = new ArrayList<Map.Entry<String,Integer>>();
for (Map.Entry<String, Integer> e: sm) {l.add(e);}
assertEquals(new MapEntry("1",1),l.get(0));
assertEquals(new MapEntry("2",2),l.get(1));
assertEquals(new MapEntry("3",3),l.get(2));
assertEquals(9999,l.size());
int i=9999;
for (Iterator<Entry<String, Integer>> rit = sm.reverseIterator();rit.hasNext();) {