Object toKey = it.next();
Object second = it.next();
Object firstValue = sm.get(first);
Object secondValue = sm.get(second);
SortedMap head = sm.headMap(toKey);
assertEquals(1, head.size());
assertEquals(true, sm.containsKey(first));
assertEquals(true, head.containsKey(first));
assertEquals(true, sm.containsValue(firstValue));
assertEquals(true, head.containsValue(firstValue));