/** pollLastEntry returns entries in order */
 public void testDescendingPollLastEntry() {
   ConcurrentNavigableMap map = dmap5();
   Map.Entry e = map.pollLastEntry();
   assertEquals(m5, e.getKey());
   assertEquals("E", e.getValue());
   e = map.pollLastEntry();
   assertEquals(m4, e.getKey());
   map.put(m5, "E");
   e = map.pollLastEntry();
   assertEquals(m5, e.getKey());
   assertEquals("E", e.getValue());
   e = map.pollLastEntry();
   assertEquals(m3, e.getKey());
   map.remove(m2);
   e = map.pollLastEntry();
   assertEquals(m1, e.getKey());
   try {
     e.setValue("E");
     shouldThrow();
   } catch (UnsupportedOperationException success) {
   }
   e = map.pollLastEntry();
   assertNull(e);
 }
 /** pollLastEntry returns entries in order */
 public void testPollLastEntry() {
   ConcurrentNavigableMap map = map5();
   Map.Entry e = map.pollLastEntry();
   assertEquals(five, e.getKey());
   assertEquals("E", e.getValue());
   e = map.pollLastEntry();
   assertEquals(four, e.getKey());
   map.put(five, "E");
   e = map.pollLastEntry();
   assertEquals(five, e.getKey());
   assertEquals("E", e.getValue());
   e = map.pollLastEntry();
   assertEquals(three, e.getKey());
   map.remove(two);
   e = map.pollLastEntry();
   assertEquals(one, e.getKey());
   try {
     e.setValue("E");
     shouldThrow();
   } catch (UnsupportedOperationException success) {
   }
   e = map.pollLastEntry();
   assertNull(e);
 }