public void testDescendingPollFirstEntry() {
ConcurrentNavigableMap map = dmap5();
Map.Entry e = map.pollFirstEntry();
assertEquals(m1, e.getKey());
assertEquals("A", e.getValue());
e = map.pollFirstEntry();
assertEquals(m2, e.getKey());
map.put(m1, "A");
e = map.pollFirstEntry();
assertEquals(m1, e.getKey());
assertEquals("A", e.getValue());