--- jsr166/src/test/tck/ConcurrentSkipListSubMapTest.java	2009/11/21 10:25:05	1.10
+++ jsr166/src/test/tck/ConcurrentSkipListSubMapTest.java	2011/05/27 19:21:27	1.18
@@ -1,7 +1,7 @@
 /*
  * Written by Doug Lea with assistance from members of JCP JSR-166
  * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
+ * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
 import junit.framework.*;
@@ -11,7 +11,7 @@ import java.io.*;
 
 public class ConcurrentSkipListSubMapTest extends JSR166TestCase {
     public static void main(String[] args) {
-        junit.textui.TestRunner.run (suite());
+        junit.textui.TestRunner.run(suite());
     }
     public static Test suite() {
         return new TestSuite(ConcurrentSkipListSubMapTest.class);
@@ -64,7 +64,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  clear removes all pairs
+     * clear removes all pairs
      */
     public void testClear() {
         ConcurrentNavigableMap map = map5();
@@ -72,9 +72,8 @@ public class ConcurrentSkipListSubMapTes
         assertEquals(map.size(), 0);
     }
 
-
     /**
-     *  Maps with same contents are equal
+     * Maps with same contents are equal
      */
     public void testEquals() {
         ConcurrentNavigableMap map1 = map5();
@@ -87,7 +86,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  containsKey returns true for contained key
+     * containsKey returns true for contained key
      */
     public void testContainsKey() {
         ConcurrentNavigableMap map = map5();
@@ -96,7 +95,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  containsValue returns true for held values
+     * containsValue returns true for held values
      */
     public void testContainsValue() {
         ConcurrentNavigableMap map = map5();
@@ -105,8 +104,8 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  get returns the correct element at the given key,
-     *  or null if not present
+     * get returns the correct element at the given key,
+     * or null if not present
      */
     public void testGet() {
         ConcurrentNavigableMap map = map5();
@@ -116,7 +115,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  isEmpty is true of empty map and false for non-empty
+     * isEmpty is true of empty map and false for non-empty
      */
     public void testIsEmpty() {
         ConcurrentNavigableMap empty = map0();
@@ -126,7 +125,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   firstKey returns first key
+     * firstKey returns first key
      */
     public void testFirstKey() {
         ConcurrentNavigableMap map = map5();
@@ -134,16 +133,15 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   lastKey returns last key
+     * lastKey returns last key
      */
     public void testLastKey() {
         ConcurrentNavigableMap map = map5();
         assertEquals(five, map.lastKey());
     }
 
-
     /**
-     *   keySet returns a Set containing all the keys
+     * keySet returns a Set containing all the keys
      */
     public void testKeySet() {
         ConcurrentNavigableMap map = map5();
@@ -157,7 +155,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   keySet is ordered
+     * keySet is ordered
      */
     public void testKeySetOrder() {
         ConcurrentNavigableMap map = map5();
@@ -187,7 +185,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  keySet.toArray returns contains all keys
+     * keySet.toArray returns contains all keys
      */
     public void testKeySetToArray() {
         ConcurrentNavigableMap map = map5();
@@ -200,7 +198,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  descendingkeySet.toArray returns contains all keys
+     * descendingkeySet.toArray returns contains all keys
      */
     public void testDescendingKeySetToArray() {
         ConcurrentNavigableMap map = map5();
@@ -213,7 +211,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  Values.toArray contains all values
+     * Values.toArray contains all values
      */
     public void testValuesToArray() {
         ConcurrentNavigableMap map = map5();
@@ -228,7 +226,6 @@ public class ConcurrentSkipListSubMapTes
         assertTrue(s.contains("E"));
     }
 
-
     /**
      * entrySet contains all pairs
      */
@@ -249,7 +246,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   putAll  adds all key-value pairs from the given map
+     * putAll adds all key-value pairs from the given map
      */
     public void testPutAll() {
         ConcurrentNavigableMap empty = map0();
@@ -264,7 +261,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   putIfAbsent works when the given key is not present
+     * putIfAbsent works when the given key is not present
      */
     public void testPutIfAbsent() {
         ConcurrentNavigableMap map = map5();
@@ -273,7 +270,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   putIfAbsent does not add the pair if the key is already present
+     * putIfAbsent does not add the pair if the key is already present
      */
     public void testPutIfAbsent2() {
         ConcurrentNavigableMap map = map5();
@@ -281,7 +278,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   replace fails when the given key is not present
+     * replace fails when the given key is not present
      */
     public void testReplace() {
         ConcurrentNavigableMap map = map5();
@@ -290,7 +287,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   replace succeeds if the key is already present
+     * replace succeeds if the key is already present
      */
     public void testReplace2() {
         ConcurrentNavigableMap map = map5();
@@ -298,7 +295,6 @@ public class ConcurrentSkipListSubMapTes
         assertEquals("Z", map.get(one));
     }
 
-
     /**
      * replace value fails when the given key not mapped to expected value
      */
@@ -319,9 +315,8 @@ public class ConcurrentSkipListSubMapTes
         assertEquals("Z", map.get(one));
     }
 
-
     /**
-     *   remove removes the correct key-value pair from the map
+     * remove removes the correct key-value pair from the map
      */
     public void testRemove() {
         ConcurrentNavigableMap map = map5();
@@ -343,7 +338,6 @@ public class ConcurrentSkipListSubMapTes
         map.remove(four, "A");
         assertEquals(4, map.size());
         assertTrue(map.containsKey(four));
-
     }
 
     /**
@@ -362,7 +356,6 @@ public class ConcurrentSkipListSubMapTes
 
         Map.Entry e4 = map.lowerEntry(zero);
         assertNull(e4);
-
     }
 
     /**
@@ -381,7 +374,6 @@ public class ConcurrentSkipListSubMapTes
 
         Map.Entry e4 = map.higherEntry(six);
         assertNull(e4);
-
     }
 
     /**
@@ -400,7 +392,6 @@ public class ConcurrentSkipListSubMapTes
 
         Map.Entry e4 = map.floorEntry(zero);
         assertNull(e4);
-
     }
 
     /**
@@ -419,7 +410,6 @@ public class ConcurrentSkipListSubMapTes
 
         Map.Entry e4 = map.ceilingEntry(six);
         assertNull(e4);
-
     }
 
     /**
@@ -444,8 +434,7 @@ public class ConcurrentSkipListSubMapTes
         try {
             e.setValue("A");
             shouldThrow();
-        } catch (Exception ok) {
-        }
+        } catch (UnsupportedOperationException success) {}
         e = map.pollFirstEntry();
         assertNull(e);
     }
@@ -472,14 +461,13 @@ public class ConcurrentSkipListSubMapTes
         try {
             e.setValue("E");
             shouldThrow();
-        } catch (Exception ok) {
-        }
+        } catch (UnsupportedOperationException success) {}
         e = map.pollLastEntry();
         assertNull(e);
     }
 
     /**
-     *   size returns the correct values
+     * size returns the correct values
      */
     public void testSize() {
         ConcurrentNavigableMap map = map5();
@@ -495,7 +483,7 @@ public class ConcurrentSkipListSubMapTes
         ConcurrentNavigableMap map = map5();
         String s = map.toString();
         for (int i = 1; i <= 5; ++i) {
-            assertTrue(s.indexOf(String.valueOf(i)) >= 0);
+            assertTrue(s.contains(String.valueOf(i)));
         }
     }
 
@@ -509,7 +497,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = map5();
             c.get(null);
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -520,7 +508,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = map5();
             c.containsKey(null);
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -531,10 +519,9 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = map0();
             c.containsValue(null);
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
-
     /**
      * put(null,x) throws NPE
      */
@@ -543,7 +530,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = map5();
             c.put(null, "whatever");
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -554,7 +541,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = map5();
             c.putIfAbsent(null, "whatever");
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -565,7 +552,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = map5();
             c.replace(null, "whatever");
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -576,7 +563,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = map5();
             c.replace(null, one, "whatever");
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -587,7 +574,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = map5();
             c.remove(null);
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -598,7 +585,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = map5();
             c.remove(null, "whatever");
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -620,8 +607,6 @@ public class ConcurrentSkipListSubMapTes
         assertTrue(r.equals(q));
     }
 
-
-
     /**
      * subMap returns map with keys in requested range
      */
@@ -651,7 +636,7 @@ public class ConcurrentSkipListSubMapTes
         assertEquals(1, sm.size());
         assertEquals(three, sm.firstKey());
         assertEquals(three, sm.lastKey());
-        assertTrue(sm.remove(three) != null);
+        assertEquals("C", sm.remove(three));
         assertTrue(sm.isEmpty());
         assertEquals(3, map.size());
     }
@@ -679,7 +664,7 @@ public class ConcurrentSkipListSubMapTes
         assertEquals(4, map.size());
         assertEquals(0, sm.size());
         assertTrue(sm.isEmpty());
-        assertTrue(sm.remove(three) == null);
+        assertSame(sm.remove(three), null);
         assertEquals(4, map.size());
     }
 
@@ -751,14 +736,14 @@ public class ConcurrentSkipListSubMapTes
         SortedMap ssm = sm.tailMap(four);
         assertEquals(four, ssm.firstKey());
         assertEquals(five, ssm.lastKey());
-        assertTrue(ssm.remove(four) != null);
+        assertEquals("D", ssm.remove(four));
         assertEquals(1, ssm.size());
         assertEquals(3, sm.size());
         assertEquals(4, map.size());
     }
 
     /**
-     *  clear removes all pairs
+     * clear removes all pairs
      */
     public void testDescendingClear() {
         ConcurrentNavigableMap map = dmap5();
@@ -766,9 +751,8 @@ public class ConcurrentSkipListSubMapTes
         assertEquals(map.size(), 0);
     }
 
-
     /**
-     *  Maps with same contents are equal
+     * Maps with same contents are equal
      */
     public void testDescendingEquals() {
         ConcurrentNavigableMap map1 = dmap5();
@@ -781,7 +765,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  containsKey returns true for contained key
+     * containsKey returns true for contained key
      */
     public void testDescendingContainsKey() {
         ConcurrentNavigableMap map = dmap5();
@@ -790,7 +774,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  containsValue returns true for held values
+     * containsValue returns true for held values
      */
     public void testDescendingContainsValue() {
         ConcurrentNavigableMap map = dmap5();
@@ -799,8 +783,8 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  get returns the correct element at the given key,
-     *  or null if not present
+     * get returns the correct element at the given key,
+     * or null if not present
      */
     public void testDescendingGet() {
         ConcurrentNavigableMap map = dmap5();
@@ -810,7 +794,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  isEmpty is true of empty map and false for non-empty
+     * isEmpty is true of empty map and false for non-empty
      */
     public void testDescendingIsEmpty() {
         ConcurrentNavigableMap empty = dmap0();
@@ -820,7 +804,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   firstKey returns first key
+     * firstKey returns first key
      */
     public void testDescendingFirstKey() {
         ConcurrentNavigableMap map = dmap5();
@@ -828,16 +812,15 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   lastKey returns last key
+     * lastKey returns last key
      */
     public void testDescendingLastKey() {
         ConcurrentNavigableMap map = dmap5();
         assertEquals(m5, map.lastKey());
     }
 
-
     /**
-     *   keySet returns a Set containing all the keys
+     * keySet returns a Set containing all the keys
      */
     public void testDescendingKeySet() {
         ConcurrentNavigableMap map = dmap5();
@@ -851,7 +834,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   keySet is ordered
+     * keySet is ordered
      */
     public void testDescendingKeySetOrder() {
         ConcurrentNavigableMap map = dmap5();
@@ -881,7 +864,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  keySet.toArray returns contains all keys
+     * keySet.toArray returns contains all keys
      */
     public void testDescendingAscendingKeySetToArray() {
         ConcurrentNavigableMap map = dmap5();
@@ -894,7 +877,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  descendingkeySet.toArray returns contains all keys
+     * descendingkeySet.toArray returns contains all keys
      */
     public void testDescendingDescendingKeySetToArray() {
         ConcurrentNavigableMap map = dmap5();
@@ -907,7 +890,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *  Values.toArray contains all values
+     * Values.toArray contains all values
      */
     public void testDescendingValuesToArray() {
         ConcurrentNavigableMap map = dmap5();
@@ -922,7 +905,6 @@ public class ConcurrentSkipListSubMapTes
         assertTrue(s.contains("E"));
     }
 
-
     /**
      * entrySet contains all pairs
      */
@@ -943,7 +925,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   putAll  adds all key-value pairs from the given map
+     * putAll adds all key-value pairs from the given map
      */
     public void testDescendingPutAll() {
         ConcurrentNavigableMap empty = dmap0();
@@ -958,7 +940,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   putIfAbsent works when the given key is not present
+     * putIfAbsent works when the given key is not present
      */
     public void testDescendingPutIfAbsent() {
         ConcurrentNavigableMap map = dmap5();
@@ -967,7 +949,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   putIfAbsent does not add the pair if the key is already present
+     * putIfAbsent does not add the pair if the key is already present
      */
     public void testDescendingPutIfAbsent2() {
         ConcurrentNavigableMap map = dmap5();
@@ -975,7 +957,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   replace fails when the given key is not present
+     * replace fails when the given key is not present
      */
     public void testDescendingReplace() {
         ConcurrentNavigableMap map = dmap5();
@@ -984,7 +966,7 @@ public class ConcurrentSkipListSubMapTes
     }
 
     /**
-     *   replace succeeds if the key is already present
+     * replace succeeds if the key is already present
      */
     public void testDescendingReplace2() {
         ConcurrentNavigableMap map = dmap5();
@@ -992,7 +974,6 @@ public class ConcurrentSkipListSubMapTes
         assertEquals("Z", map.get(m1));
     }
 
-
     /**
      * replace value fails when the given key not mapped to expected value
      */
@@ -1013,9 +994,8 @@ public class ConcurrentSkipListSubMapTes
         assertEquals("Z", map.get(m1));
     }
 
-
     /**
-     *   remove removes the correct key-value pair from the map
+     * remove removes the correct key-value pair from the map
      */
     public void testDescendingRemove() {
         ConcurrentNavigableMap map = dmap5();
@@ -1037,7 +1017,6 @@ public class ConcurrentSkipListSubMapTes
         map.remove(m4, "A");
         assertEquals(4, map.size());
         assertTrue(map.containsKey(m4));
-
     }
 
     /**
@@ -1056,7 +1035,6 @@ public class ConcurrentSkipListSubMapTes
 
         Map.Entry e4 = map.lowerEntry(zero);
         assertNull(e4);
-
     }
 
     /**
@@ -1075,7 +1053,6 @@ public class ConcurrentSkipListSubMapTes
 
         Map.Entry e4 = map.higherEntry(m6);
         assertNull(e4);
-
     }
 
     /**
@@ -1094,7 +1071,6 @@ public class ConcurrentSkipListSubMapTes
 
         Map.Entry e4 = map.floorEntry(zero);
         assertNull(e4);
-
     }
 
     /**
@@ -1113,7 +1089,6 @@ public class ConcurrentSkipListSubMapTes
 
         Map.Entry e4 = map.ceilingEntry(m6);
         assertNull(e4);
-
     }
 
     /**
@@ -1138,8 +1113,7 @@ public class ConcurrentSkipListSubMapTes
         try {
             e.setValue("A");
             shouldThrow();
-        } catch (Exception ok) {
-        }
+        } catch (UnsupportedOperationException success) {}
         e = map.pollFirstEntry();
         assertNull(e);
     }
@@ -1166,14 +1140,13 @@ public class ConcurrentSkipListSubMapTes
         try {
             e.setValue("E");
             shouldThrow();
-        } catch (Exception ok) {
-        }
+        } catch (UnsupportedOperationException success) {}
         e = map.pollLastEntry();
         assertNull(e);
     }
 
     /**
-     *   size returns the correct values
+     * size returns the correct values
      */
     public void testDescendingSize() {
         ConcurrentNavigableMap map = dmap5();
@@ -1189,32 +1162,32 @@ public class ConcurrentSkipListSubMapTes
         ConcurrentNavigableMap map = dmap5();
         String s = map.toString();
         for (int i = 1; i <= 5; ++i) {
-            assertTrue(s.indexOf(String.valueOf(i)) >= 0);
+            assertTrue(s.contains(String.valueOf(i)));
         }
     }
 
     // Exception testDescendings
 
     /**
-     * get(null) of nm1mpty map throws NPE
+     * get(null) of empty map throws NPE
      */
     public void testDescendingGet_NullPointerException() {
         try {
             ConcurrentNavigableMap c = dmap5();
             c.get(null);
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
-     * containsKey(null) of nm1mpty map throws NPE
+     * containsKey(null) of empty map throws NPE
      */
     public void testDescendingContainsKey_NullPointerException() {
         try {
             ConcurrentNavigableMap c = dmap5();
             c.containsKey(null);
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -1225,10 +1198,9 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = dmap0();
             c.containsValue(null);
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
-
     /**
      * put(null,x) throws NPE
      */
@@ -1237,7 +1209,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = dmap5();
             c.put(null, "whatever");
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -1248,7 +1220,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = dmap5();
             c.putIfAbsent(null, "whatever");
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -1259,7 +1231,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = dmap5();
             c.replace(null, "whatever");
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -1270,7 +1242,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = dmap5();
             c.replace(null, m1, "whatever");
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -1281,7 +1253,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = dmap5();
             c.remove(null);
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -1292,7 +1264,7 @@ public class ConcurrentSkipListSubMapTes
             ConcurrentNavigableMap c = dmap5();
             c.remove(null, "whatever");
             shouldThrow();
-        } catch (NullPointerException e) {}
+        } catch (NullPointerException success) {}
     }
 
     /**
@@ -1314,7 +1286,6 @@ public class ConcurrentSkipListSubMapTes
         assertTrue(r.equals(q));
     }
 
-
     /**
      * subMap returns map with keys in requested range
      */
@@ -1344,7 +1315,7 @@ public class ConcurrentSkipListSubMapTes
         assertEquals(1, sm.size());
         assertEquals(m3, sm.firstKey());
         assertEquals(m3, sm.lastKey());
-        assertTrue(sm.remove(m3) != null);
+        assertEquals("C", sm.remove(m3));
         assertTrue(sm.isEmpty());
         assertEquals(3, map.size());
     }
@@ -1372,7 +1343,7 @@ public class ConcurrentSkipListSubMapTes
         assertEquals(4, map.size());
         assertEquals(0, sm.size());
         assertTrue(sm.isEmpty());
-        assertTrue(sm.remove(m3) == null);
+        assertSame(sm.remove(m3), null);
         assertEquals(4, map.size());
     }
 
@@ -1444,7 +1415,7 @@ public class ConcurrentSkipListSubMapTes
         SortedMap ssm = sm.tailMap(m4);
         assertEquals(m4, ssm.firstKey());
         assertEquals(m5, ssm.lastKey());
-        assertTrue(ssm.remove(m4) != null);
+        assertEquals("D", ssm.remove(m4));
         assertEquals(1, ssm.size());
         assertEquals(3, sm.size());
         assertEquals(4, map.size());