--- jsr166/src/test/tck/TreeMapTest.java	2004/12/28 16:15:59	1.1
+++ jsr166/src/test/tck/TreeMapTest.java	2021/01/26 13:33:06	1.36
@@ -1,222 +1,284 @@
 /*
  * 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.*;
-import java.util.*;
-import java.util.concurrent.*;
-import java.io.*;
+import java.util.Arrays;
+import java.util.BitSet;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.NavigableMap;
+import java.util.NavigableSet;
+import java.util.NoSuchElementException;
+import java.util.Random;
+import java.util.Set;
+import java.util.TreeMap;
+
+import junit.framework.Test;
 
 public class TreeMapTest extends JSR166TestCase {
     public static void main(String[] args) {
-	junit.textui.TestRunner.run (suite());	
+        main(suite(), args);
     }
     public static Test suite() {
-	return new TestSuite(TreeMapTest.class);
+        class Implementation implements MapImplementation {
+            public Class<?> klazz() { return TreeMap.class; }
+            public Map emptyMap() { return new TreeMap(); }
+            public boolean isConcurrent() { return false; }
+            public boolean permitsNullKeys() { return false; }
+            public boolean permitsNullValues() { return true; }
+            public boolean supportsSetValue() { return true; }
+        }
+        return newTestSuite(
+            TreeMapTest.class,
+            MapTest.testSuite(new Implementation()));
     }
 
     /**
-     * Create a map from Integers 1-5 to Strings "A"-"E".
+     * Returns a new map from Items 1-5 to Strings "A"-"E".
      */
-    private static TreeMap map5() {   
-	TreeMap map = new TreeMap();
+    private static TreeMap<Item,String> map5() {
+        TreeMap<Item,String> map = new TreeMap<Item,String>();
         assertTrue(map.isEmpty());
-	map.put(one, "A");
-	map.put(five, "E");
-	map.put(three, "C");
-	map.put(two, "B");
-	map.put(four, "D");
+        map.put(one, "A");
+        map.put(five, "E");
+        map.put(three, "C");
+        map.put(two, "B");
+        map.put(four, "D");
         assertFalse(map.isEmpty());
-        assertEquals(5, map.size());
-	return map;
+        mustEqual(5, map.size());
+        return map;
     }
 
     /**
-     *  clear removes all pairs
+     * clear removes all pairs
      */
     public void testClear() {
-        TreeMap map = map5();
-	map.clear();
-	assertEquals(map.size(), 0);
+        TreeMap<Item,String> map = map5();
+        map.clear();
+        mustEqual(0, map.size());
     }
 
     /**
-     *  
+     * copy constructor creates map equal to source map
      */
     public void testConstructFromSorted() {
-        TreeMap map = map5();
-        TreeMap map2 = new TreeMap(map);
-        assertEquals(map, map2);
+        TreeMap<Item,String> map = map5();
+        TreeMap<Item,String> map2 = new TreeMap<Item,String>(map);
+        mustEqual(map, map2);
     }
 
     /**
-     *  Maps with same contents are equal
+     * Maps with same contents are equal
      */
     public void testEquals() {
-        TreeMap map1 = map5();
-        TreeMap map2 = map5();
-        assertEquals(map1, map2);
-        assertEquals(map2, map1);
-	map1.clear();
+        TreeMap<Item,String> map1 = map5();
+        TreeMap<Item,String> map2 = map5();
+        mustEqual(map1, map2);
+        mustEqual(map2, map1);
+        map1.clear();
         assertFalse(map1.equals(map2));
         assertFalse(map2.equals(map1));
     }
 
     /**
-     *  containsKey returns true for contained key
+     * containsKey returns true for contained key
      */
     public void testContainsKey() {
-        TreeMap map = map5();
-	assertTrue(map.containsKey(one));
+        TreeMap<Item,String> map = map5();
+        assertTrue(map.containsKey(one));
         assertFalse(map.containsKey(zero));
     }
 
     /**
-     *  containsValue returns true for held values
+     * containsValue returns true for held values
      */
     public void testContainsValue() {
-        TreeMap map = map5();
-	assertTrue(map.containsValue("A"));
+        TreeMap<Item,String> map = map5();
+        assertTrue(map.containsValue("A"));
         assertFalse(map.containsValue("Z"));
     }
 
     /**
-     *  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() {
-        TreeMap map = map5();
-	assertEquals("A", (String)map.get(one));
-        TreeMap empty = new TreeMap();
+        TreeMap<Item,String> map = map5();
+        mustEqual("A", map.get(one));
+        TreeMap<Item,String> empty = new TreeMap<Item,String>();
         assertNull(empty.get(one));
     }
 
     /**
-     *  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() {
-        TreeMap empty = new TreeMap();
-        TreeMap map = map5();
-	assertTrue(empty.isEmpty());
+        TreeMap<Item,String> empty = new TreeMap<Item,String>();
+        TreeMap<Item,String> map = map5();
+        assertTrue(empty.isEmpty());
         assertFalse(map.isEmpty());
     }
 
     /**
-     *   firstKey returns first key
+     * firstKey returns first key
      */
     public void testFirstKey() {
-        TreeMap map = map5();
-	assertEquals(one, map.firstKey());
+        TreeMap<Item,String> map = map5();
+        mustEqual(one, map.firstKey());
     }
 
     /**
-     *   lastKey returns last key
+     * lastKey returns last key
      */
     public void testLastKey() {
-        TreeMap map = map5();
-	assertEquals(five, map.lastKey());
+        TreeMap<Item,String> map = map5();
+        mustEqual(five, map.lastKey());
     }
 
-
     /**
-     *  keySet.toArray returns contains all keys
+     * keySet.toArray returns contains all keys
      */
     public void testKeySetToArray() {
-        TreeMap map = map5();
-	Set s = map.keySet();
+        TreeMap<Item,String> map = map5();
+        Set<Item> s = map.keySet();
         Object[] ar = s.toArray();
         assertTrue(s.containsAll(Arrays.asList(ar)));
-	assertEquals(5, ar.length);
-        ar[0] = m10;
+        mustEqual(5, ar.length);
+        ar[0] = minusTen;
         assertFalse(s.containsAll(Arrays.asList(ar)));
     }
 
     /**
-     *  descendingkeySet.toArray returns contains all keys
+     * descendingkeySet.toArray returns contains all keys
      */
     public void testDescendingKeySetToArray() {
-        TreeMap map = map5();
-	Set s = map.descendingKeySet();
+        TreeMap<Item,String> map = map5();
+        Set<Item> s = map.descendingKeySet();
         Object[] ar = s.toArray();
-	assertEquals(5, ar.length);
+        mustEqual(5, ar.length);
         assertTrue(s.containsAll(Arrays.asList(ar)));
-        ar[0] = m10;
+        ar[0] = minusTen;
         assertFalse(s.containsAll(Arrays.asList(ar)));
     }
 
     /**
-     *   keySet returns a Set containing all the keys
+     * keySet returns a Set containing all the keys
      */
     public void testKeySet() {
-        TreeMap map = map5();
-	Set s = map.keySet();
-	assertEquals(5, s.size());
-	assertTrue(s.contains(one));
-	assertTrue(s.contains(two));
-	assertTrue(s.contains(three));
-	assertTrue(s.contains(four));
-	assertTrue(s.contains(five));
+        TreeMap<Item,String> map = map5();
+        Set<Item> s = map.keySet();
+        mustEqual(5, s.size());
+        mustContain(s, one);
+        mustContain(s, two);
+        mustContain(s, three);
+        mustContain(s, four);
+        mustContain(s, five);
     }
 
     /**
-     *   keySet is ordered
+     * keySet is ordered
      */
     public void testKeySetOrder() {
-        TreeMap map = map5();
-	Set s = map.keySet();
-        Iterator i = s.iterator();
-        Integer last = (Integer)i.next();
-        assertEquals(last, one);
+        TreeMap<Item,String> map = map5();
+        Set<Item> s = map.keySet();
+        Iterator<? extends Item> i = s.iterator();
+        Item last = i.next();
+        mustEqual(last, one);
+        int count = 1;
         while (i.hasNext()) {
-            Integer k = (Integer)i.next();
+            Item k = i.next();
             assertTrue(last.compareTo(k) < 0);
             last = k;
+            ++count;
         }
+        mustEqual(5, count);
     }
 
     /**
-     *   descendingKeySet is ordered
+     * descending iterator of key set is inverse ordered
+     */
+    public void testKeySetDescendingIteratorOrder() {
+        TreeMap<Item,String> map = map5();
+        NavigableSet<Item> s = map.navigableKeySet();
+        Iterator<? extends Item> i = s.descendingIterator();
+        Item last = (Item)i.next();
+        mustEqual(last, five);
+        int count = 1;
+        while (i.hasNext()) {
+            Item k = (Item)i.next();
+            assertTrue(last.compareTo(k) > 0);
+            last = k;
+            ++count;
+        }
+        mustEqual(5, count);
+    }
+
+    /**
+     * descendingKeySet is ordered
      */
     public void testDescendingKeySetOrder() {
-        TreeMap map = map5();
-	Set s = map.descendingKeySet();
-        Iterator i = s.iterator();
-        Integer last = (Integer)i.next();
-        assertEquals(last, five);
+        TreeMap<Item,String> map = map5();
+        Set<Item> s = map.descendingKeySet();
+        Iterator<? extends Item> i = s.iterator();
+        Item last = (Item)i.next();
+        mustEqual(last, five);
+        int count = 1;
         while (i.hasNext()) {
-            Integer k = (Integer)i.next();
+            Item k = (Item)i.next();
             assertTrue(last.compareTo(k) > 0);
             last = k;
+            ++count;
         }
+        mustEqual(5, count);
+    }
+
+    /**
+     * descending iterator of descendingKeySet is ordered
+     */
+    public void testDescendingKeySetDescendingIteratorOrder() {
+        TreeMap<Item,String> map = map5();
+        NavigableSet<Item> s = map.descendingKeySet();
+        Iterator<? extends Item> i = s.descendingIterator();
+        Item last = (Item)i.next();
+        mustEqual(last, one);
+        int count = 1;
+        while (i.hasNext()) {
+            Item k = (Item)i.next();
+            assertTrue(last.compareTo(k) < 0);
+            last = k;
+            ++count;
+        }
+        mustEqual(5, count);
     }
 
     /**
      * values collection contains all values
      */
     public void testValues() {
-        TreeMap map = map5();
-	Collection s = map.values();
-	assertEquals(5, s.size());
-	assertTrue(s.contains("A"));
-	assertTrue(s.contains("B"));
-	assertTrue(s.contains("C"));
-	assertTrue(s.contains("D"));
-	assertTrue(s.contains("E"));
+        TreeMap<Item,String> map = map5();
+        Collection<String> s = map.values();
+        mustEqual(5, s.size());
+        assertTrue(s.contains("A"));
+        assertTrue(s.contains("B"));
+        assertTrue(s.contains("C"));
+        assertTrue(s.contains("D"));
+        assertTrue(s.contains("E"));
     }
 
     /**
      * entrySet contains all pairs
      */
     public void testEntrySet() {
-        TreeMap map = map5();
-	Set s = map.entrySet();
-	assertEquals(5, s.size());
-        Iterator it = s.iterator();
+        TreeMap<Item,String> map = map5();
+        Set<Map.Entry<Item,String>> s = map.entrySet();
+        mustEqual(5, s.size());
+        Iterator<Map.Entry<Item,String>> it = s.iterator();
         while (it.hasNext()) {
-            Map.Entry e = (Map.Entry) it.next();
-            assertTrue( 
+            Map.Entry<Item,String> e = it.next();
+            assertTrue(
                        (e.getKey().equals(one) && e.getValue().equals("A")) ||
                        (e.getKey().equals(two) && e.getValue().equals("B")) ||
                        (e.getKey().equals(three) && e.getValue().equals("C")) ||
@@ -229,13 +291,13 @@ public class TreeMapTest extends JSR166T
      * descendingEntrySet contains all pairs
      */
     public void testDescendingEntrySet() {
-        TreeMap map = map5();
-	Set s = map.descendingEntrySet();
-	assertEquals(5, s.size());
-        Iterator it = s.iterator();
+        TreeMap<Item,String> map = map5();
+        Set<Map.Entry<Item,String>> s = map.descendingMap().entrySet();
+        mustEqual(5, s.size());
+        Iterator<Map.Entry<Item,String>> it = s.iterator();
         while (it.hasNext()) {
-            Map.Entry e = (Map.Entry) it.next();
-            assertTrue( 
+            Map.Entry<Item,String> e = it.next();
+            assertTrue(
                        (e.getKey().equals(one) && e.getValue().equals("A")) ||
                        (e.getKey().equals(two) && e.getValue().equals("B")) ||
                        (e.getKey().equals(three) && e.getValue().equals("C")) ||
@@ -245,13 +307,13 @@ public class TreeMapTest extends JSR166T
     }
 
     /**
-     *  entrySet.toArray contains all entries
+     * entrySet.toArray contains all entries
      */
     public void testEntrySetToArray() {
-        TreeMap map = map5();
-	Set s = map.entrySet();
+        TreeMap<Item,String> map = map5();
+        Set<Map.Entry<Item,String>> s = map.entrySet();
         Object[] ar = s.toArray();
-        assertEquals(5, ar.length);
+        mustEqual(5, ar.length);
         for (int i = 0; i < 5; ++i) {
             assertTrue(map.containsKey(((Map.Entry)(ar[i])).getKey()));
             assertTrue(map.containsValue(((Map.Entry)(ar[i])).getValue()));
@@ -259,13 +321,13 @@ public class TreeMapTest extends JSR166T
     }
 
     /**
-     *  descendingEntrySet.toArray contains all entries
+     * descendingEntrySet.toArray contains all entries
      */
     public void testDescendingEntrySetToArray() {
-        TreeMap map = map5();
-	Set s = map.descendingEntrySet();
+        TreeMap<Item,String> map = map5();
+        Set<Map.Entry<Item,String>> s = map.descendingMap().entrySet();
         Object[] ar = s.toArray();
-        assertEquals(5, ar.length);
+        mustEqual(5, ar.length);
         for (int i = 0; i < 5; ++i) {
             assertTrue(map.containsKey(((Map.Entry)(ar[i])).getKey()));
             assertTrue(map.containsValue(((Map.Entry)(ar[i])).getValue()));
@@ -273,207 +335,197 @@ public class TreeMapTest extends JSR166T
     }
 
     /**
-     *   putAll  adds all key-value pairs from the given map
+     * putAll adds all key-value pairs from the given map
      */
     public void testPutAll() {
-        TreeMap empty = new TreeMap();
-        TreeMap map = map5();
-	empty.putAll(map);
-	assertEquals(5, empty.size());
-	assertTrue(empty.containsKey(one));
-	assertTrue(empty.containsKey(two));
-	assertTrue(empty.containsKey(three));
-	assertTrue(empty.containsKey(four));
-	assertTrue(empty.containsKey(five));
+        TreeMap<Item,String> empty = new TreeMap<Item,String>();
+        TreeMap<Item,String> map = map5();
+        empty.putAll(map);
+        mustEqual(5, empty.size());
+        assertTrue(empty.containsKey(one));
+        assertTrue(empty.containsKey(two));
+        assertTrue(empty.containsKey(three));
+        assertTrue(empty.containsKey(four));
+        assertTrue(empty.containsKey(five));
     }
 
     /**
-     *   remove removes the correct key-value pair from the map
+     * remove removes the correct key-value pair from the map
      */
     public void testRemove() {
-        TreeMap map = map5();
-	map.remove(five);
-	assertEquals(4, map.size());
-	assertFalse(map.containsKey(five));
+        TreeMap<Item,String> map = map5();
+        map.remove(five);
+        mustEqual(4, map.size());
+        assertFalse(map.containsKey(five));
     }
 
     /**
      * lowerEntry returns preceding entry.
      */
     public void testLowerEntry() {
-        TreeMap map = map5();
-        Map.Entry e1 = map.lowerEntry(three);
-        assertEquals(two, e1.getKey());
+        TreeMap<Item,String> map = map5();
+        Map.Entry<Item,String> e1 = map.lowerEntry(three);
+        mustEqual(two, e1.getKey());
 
-        Map.Entry e2 = map.lowerEntry(six);
-        assertEquals(five, e2.getKey());
+        Map.Entry<Item,String> e2 = map.lowerEntry(six);
+        mustEqual(five, e2.getKey());
 
-        Map.Entry e3 = map.lowerEntry(one);
+        Map.Entry<Item,String> e3 = map.lowerEntry(one);
         assertNull(e3);
 
-        Map.Entry e4 = map.lowerEntry(zero);
+        Map.Entry<Item,String> e4 = map.lowerEntry(zero);
         assertNull(e4);
-
     }
 
     /**
      * higherEntry returns next entry.
      */
     public void testHigherEntry() {
-        TreeMap map = map5();
-        Map.Entry e1 = map.higherEntry(three);
-        assertEquals(four, e1.getKey());
+        TreeMap<Item,String> map = map5();
+        Map.Entry<Item,String> e1 = map.higherEntry(three);
+        mustEqual(four, e1.getKey());
 
-        Map.Entry e2 = map.higherEntry(zero);
-        assertEquals(one, e2.getKey());
+        Map.Entry<Item,String> e2 = map.higherEntry(zero);
+        mustEqual(one, e2.getKey());
 
-        Map.Entry e3 = map.higherEntry(five);
+        Map.Entry<Item,String> e3 = map.higherEntry(five);
         assertNull(e3);
 
-        Map.Entry e4 = map.higherEntry(six);
+        Map.Entry<Item,String> e4 = map.higherEntry(six);
         assertNull(e4);
-
     }
 
     /**
      * floorEntry returns preceding entry.
      */
     public void testFloorEntry() {
-        TreeMap map = map5();
-        Map.Entry e1 = map.floorEntry(three);
-        assertEquals(three, e1.getKey());
+        TreeMap<Item,String> map = map5();
+        Map.Entry<Item,String> e1 = map.floorEntry(three);
+        mustEqual(three, e1.getKey());
 
-        Map.Entry e2 = map.floorEntry(six);
-        assertEquals(five, e2.getKey());
+        Map.Entry<Item,String> e2 = map.floorEntry(six);
+        mustEqual(five, e2.getKey());
 
-        Map.Entry e3 = map.floorEntry(one);
-        assertEquals(one, e3.getKey());
+        Map.Entry<Item,String> e3 = map.floorEntry(one);
+        mustEqual(one, e3.getKey());
 
-        Map.Entry e4 = map.floorEntry(zero);
+        Map.Entry<Item,String> e4 = map.floorEntry(zero);
         assertNull(e4);
-
     }
 
     /**
      * ceilingEntry returns next entry.
      */
     public void testCeilingEntry() {
-        TreeMap map = map5();
-        Map.Entry e1 = map.ceilingEntry(three);
-        assertEquals(three, e1.getKey());
+        TreeMap<Item,String> map = map5();
+        Map.Entry<Item,String> e1 = map.ceilingEntry(three);
+        mustEqual(three, e1.getKey());
 
-        Map.Entry e2 = map.ceilingEntry(zero);
-        assertEquals(one, e2.getKey());
+        Map.Entry<Item,String> e2 = map.ceilingEntry(zero);
+        mustEqual(one, e2.getKey());
 
-        Map.Entry e3 = map.ceilingEntry(five);
-        assertEquals(five, e3.getKey());
+        Map.Entry<Item,String> e3 = map.ceilingEntry(five);
+        mustEqual(five, e3.getKey());
 
-        Map.Entry e4 = map.ceilingEntry(six);
+        Map.Entry<Item,String> e4 = map.ceilingEntry(six);
         assertNull(e4);
-
     }
 
-
     /**
      * lowerKey returns preceding element
      */
     public void testLowerKey() {
-        TreeMap q = map5();
+        TreeMap<Item,String> q = map5();
         Object e1 = q.lowerKey(three);
-        assertEquals(two, e1);
+        mustEqual(two, e1);
 
         Object e2 = q.lowerKey(six);
-        assertEquals(five, e2);
+        mustEqual(five, e2);
 
         Object e3 = q.lowerKey(one);
         assertNull(e3);
 
         Object e4 = q.lowerKey(zero);
         assertNull(e4);
-
     }
 
     /**
      * higherKey returns next element
      */
     public void testHigherKey() {
-        TreeMap q = map5();
+        TreeMap<Item,String> q = map5();
         Object e1 = q.higherKey(three);
-        assertEquals(four, e1);
+        mustEqual(four, e1);
 
         Object e2 = q.higherKey(zero);
-        assertEquals(one, e2);
+        mustEqual(one, e2);
 
         Object e3 = q.higherKey(five);
         assertNull(e3);
 
         Object e4 = q.higherKey(six);
         assertNull(e4);
-
     }
 
     /**
      * floorKey returns preceding element
      */
     public void testFloorKey() {
-        TreeMap q = map5();
+        TreeMap<Item,String> q = map5();
         Object e1 = q.floorKey(three);
-        assertEquals(three, e1);
+        mustEqual(three, e1);
 
         Object e2 = q.floorKey(six);
-        assertEquals(five, e2);
+        mustEqual(five, e2);
 
         Object e3 = q.floorKey(one);
-        assertEquals(one, e3);
+        mustEqual(one, e3);
 
         Object e4 = q.floorKey(zero);
         assertNull(e4);
-
     }
 
     /**
      * ceilingKey returns next element
      */
     public void testCeilingKey() {
-        TreeMap q = map5();
+        TreeMap<Item,String> q = map5();
         Object e1 = q.ceilingKey(three);
-        assertEquals(three, e1);
+        mustEqual(three, e1);
 
         Object e2 = q.ceilingKey(zero);
-        assertEquals(one, e2);
+        mustEqual(one, e2);
 
         Object e3 = q.ceilingKey(five);
-        assertEquals(five, e3);
+        mustEqual(five, e3);
 
         Object e4 = q.ceilingKey(six);
         assertNull(e4);
-
     }
 
     /**
      * pollFirstEntry returns entries in order
      */
     public void testPollFirstEntry() {
-        TreeMap map = map5();
-        Map.Entry e = map.pollFirstEntry();
-        assertEquals(one, e.getKey());
-        assertEquals("A", e.getValue());
+        TreeMap<Item,String> map = map5();
+        Map.Entry<Item,String> e = map.pollFirstEntry();
+        mustEqual(one, e.getKey());
+        mustEqual("A", e.getValue());
         e = map.pollFirstEntry();
-        assertEquals(two, e.getKey());
+        mustEqual(two, e.getKey());
         map.put(one, "A");
         e = map.pollFirstEntry();
-        assertEquals(one, e.getKey());
-        assertEquals("A", e.getValue());
+        mustEqual(one, e.getKey());
+        mustEqual("A", e.getValue());
         e = map.pollFirstEntry();
-        assertEquals(three, e.getKey());
+        mustEqual(three, e.getKey());
         map.remove(four);
         e = map.pollFirstEntry();
-        assertEquals(five, e.getKey());
+        mustEqual(five, e.getKey());
         try {
             e.setValue("A");
             shouldThrow();
-        } catch (Exception ok) {
-        }
+        } catch (UnsupportedOperationException success) {}
         e = map.pollFirstEntry();
         assertNull(e);
     }
@@ -482,50 +534,49 @@ public class TreeMapTest extends JSR166T
      * pollLastEntry returns entries in order
      */
     public void testPollLastEntry() {
-        TreeMap map = map5();
-        Map.Entry e = map.pollLastEntry();
-        assertEquals(five, e.getKey());
-        assertEquals("E", e.getValue());
+        TreeMap<Item,String> map = map5();
+        Map.Entry<Item,String> e = map.pollLastEntry();
+        mustEqual(five, e.getKey());
+        mustEqual("E", e.getValue());
         e = map.pollLastEntry();
-        assertEquals(four, e.getKey());
+        mustEqual(four, e.getKey());
         map.put(five, "E");
         e = map.pollLastEntry();
-        assertEquals(five, e.getKey());
-        assertEquals("E", e.getValue());
+        mustEqual(five, e.getKey());
+        mustEqual("E", e.getValue());
         e = map.pollLastEntry();
-        assertEquals(three, e.getKey());
+        mustEqual(three, e.getKey());
         map.remove(two);
         e = map.pollLastEntry();
-        assertEquals(one, e.getKey());
+        mustEqual(one, e.getKey());
         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() {
-        TreeMap map = map5();
-        TreeMap empty = new TreeMap();
-	assertEquals(0, empty.size());
-	assertEquals(5, map.size());
+        TreeMap<Item,String> map = map5();
+        TreeMap<Item,String> empty = new TreeMap<Item,String>();
+        mustEqual(0, empty.size());
+        mustEqual(5, map.size());
     }
 
     /**
      * toString contains toString of elements
      */
     public void testToString() {
-        TreeMap map = map5();
+        TreeMap<Item,String> 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)));
         }
-    }        
+    }
 
     // Exception tests
 
@@ -533,215 +584,511 @@ public class TreeMapTest extends JSR166T
      * get(null) of nonempty map throws NPE
      */
     public void testGet_NullPointerException() {
+        TreeMap<Item,String> c = map5();
         try {
-            TreeMap c = map5();
             c.get(null);
             shouldThrow();
-        } catch(NullPointerException e){}
+        } catch (NullPointerException success) {}
     }
 
     /**
      * containsKey(null) of nonempty map throws NPE
      */
     public void testContainsKey_NullPointerException() {
+        TreeMap<Item,String> c = map5();
         try {
-            TreeMap c = map5();
             c.containsKey(null);
             shouldThrow();
-        } catch(NullPointerException e){}
+        } catch (NullPointerException success) {}
     }
 
     /**
      * remove(null) throws NPE for nonempty map
      */
     public void testRemove1_NullPointerException() {
+        TreeMap<Item,String> c = new TreeMap<Item,String>();
+        c.put(one, "asdads");
         try {
-            TreeMap c = new TreeMap();
-            c.put("sadsdf", "asdads");
             c.remove(null);
             shouldThrow();
-        } catch(NullPointerException e){}
+        } catch (NullPointerException success) {}
     }
 
     /**
-     * A deserialized map equals original
+     * A deserialized/reserialized map equals original
      */
-    public void testSerialization() {
-        TreeMap q = map5();
+    public void testSerialization() throws Exception {
+        NavigableMap<Item,String> x = map5();
+        NavigableMap<Item,String> y = serialClone(x);
 
-        try {
-            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
-            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
-            out.writeObject(q);
-            out.close();
-
-            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
-            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
-            TreeMap r = (TreeMap)in.readObject();
-            assertEquals(q.size(), r.size());
-            assertTrue(q.equals(r));
-            assertTrue(r.equals(q));
-        } catch(Exception e){
-            e.printStackTrace();
-            unexpectedException();
-        }
+        assertNotSame(x, y);
+        mustEqual(x.size(), y.size());
+        mustEqual(x.toString(), y.toString());
+        mustEqual(x, y);
+        mustEqual(y, x);
     }
 
     /**
      * subMap returns map with keys in requested range
      */
     public void testSubMapContents() {
-        TreeMap map = map5();
-        NavigableMap sm = map.subMap(two, four);
-        assertEquals(two, sm.firstKey());
-        assertEquals(three, sm.lastKey());
-        assertEquals(2, sm.size());
+        TreeMap<Item,String> map = map5();
+        NavigableMap<Item,String> sm = map.subMap(two, true, four, false);
+        mustEqual(two, sm.firstKey());
+        mustEqual(three, sm.lastKey());
+        mustEqual(2, sm.size());
         assertFalse(sm.containsKey(one));
         assertTrue(sm.containsKey(two));
         assertTrue(sm.containsKey(three));
         assertFalse(sm.containsKey(four));
         assertFalse(sm.containsKey(five));
-        Iterator i = sm.keySet().iterator();
-        Object k;
-        k = (Integer)(i.next());
-        assertEquals(two, k);
-        k = (Integer)(i.next());
-        assertEquals(three, k);
+        Iterator<? extends Item> i = sm.keySet().iterator();
+        Item k;
+        k = (Item)(i.next());
+        mustEqual(two, k);
+        k = (Item)(i.next());
+        mustEqual(three, k);
         assertFalse(i.hasNext());
-        Iterator r = sm.descendingKeySet().iterator();
-        k = (Integer)(r.next());
-        assertEquals(three, k);
-        k = (Integer)(r.next());
-        assertEquals(two, k);
+        Iterator<? extends Item> r = sm.descendingKeySet().iterator();
+        k = (Item)(r.next());
+        mustEqual(three, k);
+        k = (Item)(r.next());
+        mustEqual(two, k);
         assertFalse(r.hasNext());
-        
-        Iterator j = sm.keySet().iterator();
+
+        Iterator<? extends Item> j = sm.keySet().iterator();
         j.next();
         j.remove();
         assertFalse(map.containsKey(two));
-        assertEquals(4, map.size());
-        assertEquals(1, sm.size());
-        assertEquals(three, sm.firstKey());
-        assertEquals(three, sm.lastKey());
-        assertTrue(sm.remove(three) != null);
+        mustEqual(4, map.size());
+        mustEqual(1, sm.size());
+        mustEqual(three, sm.firstKey());
+        mustEqual(three, sm.lastKey());
+        mustEqual("C", sm.remove(three));
         assertTrue(sm.isEmpty());
-        assertEquals(3, map.size());
+        mustEqual(3, map.size());
     }
 
     public void testSubMapContents2() {
-        TreeMap map = map5();
-        NavigableMap sm = map.subMap(two, three);
-        assertEquals(1, sm.size());
-        assertEquals(two, sm.firstKey());
-        assertEquals(two, sm.lastKey());
+        TreeMap<Item,String> map = map5();
+        NavigableMap<Item,String> sm = map.subMap(two, true, three, false);
+        mustEqual(1, sm.size());
+        mustEqual(two, sm.firstKey());
+        mustEqual(two, sm.lastKey());
         assertFalse(sm.containsKey(one));
         assertTrue(sm.containsKey(two));
         assertFalse(sm.containsKey(three));
         assertFalse(sm.containsKey(four));
         assertFalse(sm.containsKey(five));
-        Iterator i = sm.keySet().iterator();
-        Object k;
-        k = (Integer)(i.next());
-        assertEquals(two, k);
+        Iterator<? extends Item> i = sm.keySet().iterator();
+        Item k;
+        k = (Item)(i.next());
+        mustEqual(two, k);
         assertFalse(i.hasNext());
-        Iterator r = sm.descendingKeySet().iterator();
-        k = (Integer)(r.next());
-        assertEquals(two, k);
+        Iterator<? extends Item> r = sm.descendingKeySet().iterator();
+        k = (Item)(r.next());
+        mustEqual(two, k);
         assertFalse(r.hasNext());
-        
-        Iterator j = sm.keySet().iterator();
+
+        Iterator<? extends Item> j = sm.keySet().iterator();
         j.next();
         j.remove();
         assertFalse(map.containsKey(two));
-        assertEquals(4, map.size());
-        assertEquals(0, sm.size());
+        mustEqual(4, map.size());
+        mustEqual(0, sm.size());
         assertTrue(sm.isEmpty());
-        assertTrue(sm.remove(three) == null);
-        assertEquals(4, map.size());
+        assertSame(sm.remove(three), null);
+        mustEqual(4, map.size());
     }
 
     /**
      * headMap returns map with keys in requested range
      */
     public void testHeadMapContents() {
-        TreeMap map = map5();
-        NavigableMap sm = map.headMap(four);
+        TreeMap<Item,String> map = map5();
+        NavigableMap<Item, String> sm = map.headMap(four, false);
         assertTrue(sm.containsKey(one));
         assertTrue(sm.containsKey(two));
         assertTrue(sm.containsKey(three));
         assertFalse(sm.containsKey(four));
         assertFalse(sm.containsKey(five));
-        Iterator i = sm.keySet().iterator();
-        Object k;
-        k = (Integer)(i.next());
-        assertEquals(one, k);
-        k = (Integer)(i.next());
-        assertEquals(two, k);
-        k = (Integer)(i.next());
-        assertEquals(three, k);
+        Iterator<? extends Item> i = sm.keySet().iterator();
+        Item k;
+        k = (Item)(i.next());
+        mustEqual(one, k);
+        k = (Item)(i.next());
+        mustEqual(two, k);
+        k = (Item)(i.next());
+        mustEqual(three, k);
         assertFalse(i.hasNext());
         sm.clear();
         assertTrue(sm.isEmpty());
-        assertEquals(2, map.size());
-        assertEquals(four, map.firstKey());
+        mustEqual(2, map.size());
+        mustEqual(four, map.firstKey());
     }
 
     /**
      * headMap returns map with keys in requested range
      */
     public void testTailMapContents() {
-        TreeMap map = map5();
-        NavigableMap sm = map.tailMap(two);
+        TreeMap<Item,String> map = map5();
+        NavigableMap<Item,String> sm = map.tailMap(two, true);
         assertFalse(sm.containsKey(one));
         assertTrue(sm.containsKey(two));
         assertTrue(sm.containsKey(three));
         assertTrue(sm.containsKey(four));
         assertTrue(sm.containsKey(five));
-        Iterator i = sm.keySet().iterator();
-        Object k;
-        k = (Integer)(i.next());
-        assertEquals(two, k);
-        k = (Integer)(i.next());
-        assertEquals(three, k);
-        k = (Integer)(i.next());
-        assertEquals(four, k);
-        k = (Integer)(i.next());
-        assertEquals(five, k);
+        Iterator<? extends Item> i = sm.keySet().iterator();
+        Item k = (i.next());
+        mustEqual(two, k);
+        k = (i.next());
+        mustEqual(three, k);
+        k = (i.next());
+        mustEqual(four, k);
+        k = (i.next());
+        mustEqual(five, k);
         assertFalse(i.hasNext());
-        Iterator r = sm.descendingKeySet().iterator();
-        k = (Integer)(r.next());
-        assertEquals(five, k);
-        k = (Integer)(r.next());
-        assertEquals(four, k);
-        k = (Integer)(r.next());
-        assertEquals(three, k);
-        k = (Integer)(r.next());
-        assertEquals(two, k);
+        Iterator<? extends Item> r = sm.descendingKeySet().iterator();
+        k = (r.next());
+        mustEqual(five, k);
+        k = (r.next());
+        mustEqual(four, k);
+        k = (r.next());
+        mustEqual(three, k);
+        k = (r.next());
+        mustEqual(two, k);
         assertFalse(r.hasNext());
 
-        Iterator ei = sm.entrySet().iterator();
-        Map.Entry e;
-        e = (Map.Entry)(ei.next());
-        assertEquals(two, e.getKey());
-        assertEquals("B", e.getValue());
-        e = (Map.Entry)(ei.next());
-        assertEquals(three, e.getKey());
-        assertEquals("C", e.getValue());
-        e = (Map.Entry)(ei.next());
-        assertEquals(four, e.getKey());
-        assertEquals("D", e.getValue());
-        e = (Map.Entry)(ei.next());
-        assertEquals(five, e.getKey());
-        assertEquals("E", e.getValue());
+        Iterator<Map.Entry<Item,String>> ei = sm.entrySet().iterator();
+        Map.Entry<Item,String> e;
+        e = (ei.next());
+        mustEqual(two, e.getKey());
+        mustEqual("B", e.getValue());
+        e = (ei.next());
+        mustEqual(three, e.getKey());
+        mustEqual("C", e.getValue());
+        e = (ei.next());
+        mustEqual(four, e.getKey());
+        mustEqual("D", e.getValue());
+        e = (ei.next());
+        mustEqual(five, e.getKey());
+        mustEqual("E", e.getValue());
         assertFalse(i.hasNext());
 
-        NavigableMap ssm = sm.tailMap(four);
-        assertEquals(four, ssm.firstKey());
-        assertEquals(five, ssm.lastKey());
-        assertTrue(ssm.remove(four) != null);
-        assertEquals(1, ssm.size());
-        assertEquals(3, sm.size());
-        assertEquals(4, map.size());
+        NavigableMap<Item,String> ssm = sm.tailMap(four, true);
+        mustEqual(four, ssm.firstKey());
+        mustEqual(five, ssm.lastKey());
+        mustEqual("D", ssm.remove(four));
+        mustEqual(1, ssm.size());
+        mustEqual(3, sm.size());
+        mustEqual(4, map.size());
+    }
+
+    Random rnd = new Random(666);
+    BitSet bs;
+
+    /**
+     * Submaps of submaps subdivide correctly
+     */
+    public void testRecursiveSubMaps() throws Exception {
+        int mapSize = expensiveTests ? 1000 : 100;
+        Class<?> cl = TreeMap.class;
+        NavigableMap<Item, Item> map = newMap(cl);
+        bs = new BitSet(mapSize);
+
+        populate(map, mapSize);
+        check(map,                 0, mapSize - 1, true);
+        check(map.descendingMap(), 0, mapSize - 1, false);
+
+        mutateMap(map, 0, mapSize - 1);
+        check(map,                 0, mapSize - 1, true);
+        check(map.descendingMap(), 0, mapSize - 1, false);
+
+        bashSubMap(map.subMap(zero, true, itemFor(mapSize), false),
+                   0, mapSize - 1, true);
     }
-    
+
+    static NavigableMap<Item, Item> newMap(Class<?> cl) throws Exception {
+        @SuppressWarnings("unchecked")
+        NavigableMap<Item, Item> result
+            = (NavigableMap<Item, Item>) cl.getConstructor().newInstance();
+        mustEqual(0, result.size());
+        assertFalse(result.keySet().iterator().hasNext());
+        return result;
+    }
+
+    void populate(NavigableMap<Item, Item> map, int limit) {
+        for (int i = 0, n = 2 * limit / 3; i < n; i++) {
+            int key = rnd.nextInt(limit);
+            put(map, key);
+        }
+    }
+
+    void mutateMap(NavigableMap<Item, Item> map, int min, int max) {
+        int size = map.size();
+        int rangeSize = max - min + 1;
+
+        // Remove a bunch of entries directly
+        for (int i = 0, n = rangeSize / 2; i < n; i++) {
+            remove(map, min - 5 + rnd.nextInt(rangeSize + 10));
+        }
+
+        // Remove a bunch of entries with iterator
+        for (Iterator<Item> it = map.keySet().iterator(); it.hasNext(); ) {
+            if (rnd.nextBoolean()) {
+                bs.clear(it.next().value);
+                it.remove();
+            }
+        }
+
+        // Add entries till we're back to original size
+        while (map.size() < size) {
+            int key = min + rnd.nextInt(rangeSize);
+            assertTrue(key >= min && key <= max);
+            put(map, key);
+        }
+    }
+
+    void mutateSubMap(NavigableMap<Item, Item> map, int min, int max) {
+        int size = map.size();
+        int rangeSize = max - min + 1;
+
+        // Remove a bunch of entries directly
+        for (int i = 0, n = rangeSize / 2; i < n; i++) {
+            remove(map, min - 5 + rnd.nextInt(rangeSize + 10));
+        }
+
+        // Remove a bunch of entries with iterator
+        for (Iterator<Item> it = map.keySet().iterator(); it.hasNext(); ) {
+            if (rnd.nextBoolean()) {
+                bs.clear(it.next().value);
+                it.remove();
+            }
+        }
+
+        // Add entries till we're back to original size
+        while (map.size() < size) {
+            int key = min - 5 + rnd.nextInt(rangeSize + 10);
+            if (key >= min && key <= max) {
+                put(map, key);
+            } else {
+                try {
+                    map.put(itemFor(key), itemFor(2 * key));
+                    shouldThrow();
+                } catch (IllegalArgumentException success) {}
+            }
+        }
+    }
+
+    void put(NavigableMap<Item, Item> map, int key) {
+        if (map.put(itemFor(key), itemFor(2 * key)) == null)
+            bs.set(key);
+    }
+
+    void remove(NavigableMap<Item, Item> map, int key) {
+        if (map.remove(itemFor(key)) != null)
+            bs.clear(key);
+    }
+
+    void bashSubMap(NavigableMap<Item, Item> map,
+                    int min, int max, boolean ascending) {
+        check(map, min, max, ascending);
+        check(map.descendingMap(), min, max, !ascending);
+
+        mutateSubMap(map, min, max);
+        check(map, min, max, ascending);
+        check(map.descendingMap(), min, max, !ascending);
+
+        // Recurse
+        if (max - min < 2)
+            return;
+        int midPoint = (min + max) / 2;
+
+        // headMap - pick direction and endpoint inclusion randomly
+        boolean incl = rnd.nextBoolean();
+        NavigableMap<Item,Item> hm = map.headMap(itemFor(midPoint), incl);
+        if (ascending) {
+            if (rnd.nextBoolean())
+                bashSubMap(hm, min, midPoint - (incl ? 0 : 1), true);
+            else
+                bashSubMap(hm.descendingMap(), min, midPoint - (incl ? 0 : 1),
+                           false);
+        } else {
+            if (rnd.nextBoolean())
+                bashSubMap(hm, midPoint + (incl ? 0 : 1), max, false);
+            else
+                bashSubMap(hm.descendingMap(), midPoint + (incl ? 0 : 1), max,
+                           true);
+        }
+
+        // tailMap - pick direction and endpoint inclusion randomly
+        incl = rnd.nextBoolean();
+        NavigableMap<Item,Item> tm = map.tailMap(itemFor(midPoint),incl);
+        if (ascending) {
+            if (rnd.nextBoolean())
+                bashSubMap(tm, midPoint + (incl ? 0 : 1), max, true);
+            else
+                bashSubMap(tm.descendingMap(), midPoint + (incl ? 0 : 1), max,
+                           false);
+        } else {
+            if (rnd.nextBoolean()) {
+                bashSubMap(tm, min, midPoint - (incl ? 0 : 1), false);
+            } else {
+                bashSubMap(tm.descendingMap(), min, midPoint - (incl ? 0 : 1),
+                           true);
+            }
+        }
+
+        // subMap - pick direction and endpoint inclusion randomly
+        int rangeSize = max - min + 1;
+        int[] endpoints = new int[2];
+        endpoints[0] = min + rnd.nextInt(rangeSize);
+        endpoints[1] = min + rnd.nextInt(rangeSize);
+        Arrays.sort(endpoints);
+        boolean lowIncl = rnd.nextBoolean();
+        boolean highIncl = rnd.nextBoolean();
+        if (ascending) {
+            NavigableMap<Item,Item> sm = map.subMap(
+                itemFor(endpoints[0]), lowIncl, itemFor(endpoints[1]), highIncl);
+            if (rnd.nextBoolean())
+                bashSubMap(sm, endpoints[0] + (lowIncl ? 0 : 1),
+                           endpoints[1] - (highIncl ? 0 : 1), true);
+            else
+                bashSubMap(sm.descendingMap(), endpoints[0] + (lowIncl ? 0 : 1),
+                           endpoints[1] - (highIncl ? 0 : 1), false);
+        } else {
+            NavigableMap<Item,Item> sm = map.subMap(
+                itemFor(endpoints[1]), highIncl, itemFor(endpoints[0]), lowIncl);
+            if (rnd.nextBoolean())
+                bashSubMap(sm, endpoints[0] + (lowIncl ? 0 : 1),
+                           endpoints[1] - (highIncl ? 0 : 1), false);
+            else
+                bashSubMap(sm.descendingMap(), endpoints[0] + (lowIncl ? 0 : 1),
+                           endpoints[1] - (highIncl ? 0 : 1), true);
+        }
+    }
+
+    /**
+     * min and max are both inclusive.  If max < min, interval is empty.
+     */
+    void check(NavigableMap<Item, Item> map,
+                      final int min, final int max, final boolean ascending) {
+        class ReferenceSet {
+            int lower(int key) {
+                return ascending ? lowerAscending(key) : higherAscending(key);
+            }
+            int floor(int key) {
+                return ascending ? floorAscending(key) : ceilingAscending(key);
+            }
+            int ceiling(int key) {
+                return ascending ? ceilingAscending(key) : floorAscending(key);
+            }
+            int higher(int key) {
+                return ascending ? higherAscending(key) : lowerAscending(key);
+            }
+            int first() {
+                return ascending ? firstAscending() : lastAscending();
+            }
+            int last() {
+                return ascending ? lastAscending() : firstAscending();
+            }
+            int lowerAscending(int key) {
+                return floorAscending(key - 1);
+            }
+            int floorAscending(int key) {
+                if (key < min)
+                    return -1;
+                else if (key > max)
+                    key = max;
+
+                // BitSet should support this! Test would run much faster
+                while (key >= min) {
+                    if (bs.get(key))
+                        return key;
+                    key--;
+                }
+                return -1;
+            }
+            int ceilingAscending(int key) {
+                if (key < min)
+                    key = min;
+                else if (key > max)
+                    return -1;
+                int result = bs.nextSetBit(key);
+                return result > max ? -1 : result;
+            }
+            int higherAscending(int key) {
+                return ceilingAscending(key + 1);
+            }
+            private int firstAscending() {
+                int result = ceilingAscending(min);
+                return result > max ? -1 : result;
+            }
+            private int lastAscending() {
+                int result = floorAscending(max);
+                return result < min ? -1 : result;
+            }
+        }
+        ReferenceSet rs = new ReferenceSet();
+
+        // Test contents using containsKey
+        int size = 0;
+        for (int i = min; i <= max; i++) {
+            boolean bsContainsI = bs.get(i);
+            mustEqual(bsContainsI, map.containsKey(itemFor(i)));
+            if (bsContainsI)
+                size++;
+        }
+        mustEqual(size, map.size());
+
+        // Test contents using contains keySet iterator
+        int size2 = 0;
+        int previousKey = -1;
+        for (Item key : map.keySet()) {
+            assertTrue(bs.get(key.value));
+            size2++;
+            assertTrue(previousKey < 0 ||
+                (ascending ? key.value - previousKey > 0 : key.value - previousKey < 0));
+            previousKey = key.value;
+        }
+        mustEqual(size2, size);
+
+        // Test navigation ops
+        for (int key = min - 1; key <= max + 1; key++) {
+            Item k = itemFor(key);
+            assertEq(map.lowerKey(k), rs.lower(key));
+            assertEq(map.floorKey(k), rs.floor(key));
+            assertEq(map.higherKey(k), rs.higher(key));
+            assertEq(map.ceilingKey(k), rs.ceiling(key));
+        }
+
+        // Test extrema
+        if (map.size() != 0) {
+            assertEq(map.firstKey(), rs.first());
+            assertEq(map.lastKey(), rs.last());
+        } else {
+            mustEqual(rs.first(), -1);
+            mustEqual(rs.last(),  -1);
+            try {
+                map.firstKey();
+                shouldThrow();
+            } catch (NoSuchElementException success) {}
+            try {
+                map.lastKey();
+                shouldThrow();
+            } catch (NoSuchElementException success) {}
+        }
+    }
+
+    static void assertEq(Item i, int j) {
+        if (i == null)
+            mustEqual(j, -1);
+        else
+            mustEqual(i, j);
+    }
+
+    static boolean eq(Item i, int j) {
+        return i == null ? j == -1 : i.value == j;
+    }
+
 }