/*
* 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/publicdomain/zero/1.0/
*/
package jsr166;
import junit.framework.*;
import java.util.Arrays;
import java.util.BitSet;
import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NavigableSet;
import java.util.NoSuchElementException;
import java.util.Random;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
public class TreeSetTest extends JSR166TestCase {
static class MyReverseComparator implements Comparator {
public int compare(Object x, Object y) {
return ((Comparable)y).compareTo(x);
}
}
/**
* The number of elements to place in collections, arrays, etc.
*/
static final int SIZE = 20;
/**
* Returns a new set of given size containing consecutive
* Integers 0 ... n.
*/
private TreeSet<Integer> populatedSet(int n) {
TreeSet<Integer> q = new TreeSet<Integer>();
assertTrue(q.isEmpty());
for (int i = n-1; i >= 0; i-=2)
assertTrue(q.add(new Integer(i)));
for (int i = (n & 1); i < n; i+=2)
assertTrue(q.add(new Integer(i)));
assertFalse(q.isEmpty());
assertEquals(n, q.size());
return q;
}
/**
* Returns a new set of first 5 ints.
*/
private TreeSet set5() {
TreeSet q = new TreeSet();
assertTrue(q.isEmpty());
q.add(one);
q.add(two);
q.add(three);
q.add(four);
q.add(five);
assertEquals(5, q.size());
return q;
}
/**
* A new set has unbounded capacity
*/
public void testConstructor1() {
assertEquals(0, new TreeSet().size());
}
/**
* Initializing from null Collection throws NPE
*/
public void testConstructor3() {
try {
TreeSet q = new TreeSet((Collection)null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* Initializing from Collection of null elements throws NPE
*/
public void testConstructor4() {
try {
Integer[] ints = new Integer[SIZE];
TreeSet q = new TreeSet(Arrays.asList(ints));
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* Initializing from Collection with some null elements throws NPE
*/
public void testConstructor5() {
try {
Integer[] ints = new Integer[SIZE];
for (int i = 0; i < SIZE-1; ++i)
ints[i] = new Integer(i);
TreeSet q = new TreeSet(Arrays.asList(ints));
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* Set contains all elements of collection used to initialize
*/
public void testConstructor6() {
Integer[] ints = new Integer[SIZE];
for (int i = 0; i < SIZE; ++i)
ints[i] = new Integer(i);
TreeSet q = new TreeSet(Arrays.asList(ints));
for (int i = 0; i < SIZE; ++i)
assertEquals(ints[i], q.pollFirst());
}
/**
* The comparator used in constructor is used
*/
public void testConstructor7() {
MyReverseComparator cmp = new MyReverseComparator();
TreeSet q = new TreeSet(cmp);
assertEquals(cmp, q.comparator());
Integer[] ints = new Integer[SIZE];
for (int i = 0; i < SIZE; ++i)
ints[i] = new Integer(i);
q.addAll(Arrays.asList(ints));
for (int i = SIZE-1; i >= 0; --i)
assertEquals(ints[i], q.pollFirst());
}
/**
* isEmpty is true before add, false after
*/
public void testEmpty() {
TreeSet q = new TreeSet();
assertTrue(q.isEmpty());
q.add(new Integer(1));
assertFalse(q.isEmpty());
q.add(new Integer(2));
q.pollFirst();
q.pollFirst();
assertTrue(q.isEmpty());
}
/**
* size changes when elements added and removed
*/
public void testSize() {
TreeSet q = populatedSet(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(SIZE-i, q.size());
q.pollFirst();
}
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.size());
q.add(new Integer(i));
}
}
/**
* add(null) throws NPE if nonempty
*/
public void testAddNull() {
try {
TreeSet q = populatedSet(SIZE);
q.add(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* Add of comparable element succeeds
*/
public void testAdd() {
TreeSet q = new TreeSet();
assertTrue(q.add(zero));
assertTrue(q.add(one));
}
/**
* Add of duplicate element fails
*/
public void testAddDup() {
TreeSet q = new TreeSet();
assertTrue(q.add(zero));
assertFalse(q.add(zero));
}
/**
* Add of non-Comparable throws CCE
*/
public void testAddNonComparable() {
try {
TreeSet q = new TreeSet();
q.add(new Object());
q.add(new Object());
q.add(new Object());
shouldThrow();
} catch (ClassCastException success) {}
}
/**
* addAll(null) throws NPE
*/
public void testAddAll1() {
try {
TreeSet q = new TreeSet();
q.addAll(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* addAll of a collection with null elements throws NPE
*/
public void testAddAll2() {
try {
TreeSet q = new TreeSet();
Integer[] ints = new Integer[SIZE];
q.addAll(Arrays.asList(ints));
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* addAll of a collection with any null elements throws NPE after
* possibly adding some elements
*/
public void testAddAll3() {
try {
TreeSet q = new TreeSet();
Integer[] ints = new Integer[SIZE];
for (int i = 0; i < SIZE-1; ++i)
ints[i] = new Integer(i);
q.addAll(Arrays.asList(ints));
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* Set contains all elements of successful addAll
*/
public void testAddAll5() {
Integer[] empty = new Integer[0];
Integer[] ints = new Integer[SIZE];
for (int i = 0; i < SIZE; ++i)
ints[i] = new Integer(SIZE-1-i);
TreeSet q = new TreeSet();
assertFalse(q.addAll(Arrays.asList(empty)));
assertTrue(q.addAll(Arrays.asList(ints)));
for (int i = 0; i < SIZE; ++i)
assertEquals(new Integer(i), q.pollFirst());
}
/**
* pollFirst succeeds unless empty
*/
public void testPollFirst() {
TreeSet q = populatedSet(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertEquals(i, q.pollFirst());
}
assertNull(q.pollFirst());
}
/**
* pollLast succeeds unless empty
*/
public void testPollLast() {
TreeSet q = populatedSet(SIZE);
for (int i = SIZE-1; i >= 0; --i) {
assertEquals(i, q.pollLast());
}
assertNull(q.pollFirst());
}
/**
* remove(x) removes x and returns true if present
*/
public void testRemoveElement() {
TreeSet q = populatedSet(SIZE);
for (int i = 1; i < SIZE; i+=2) {
assertTrue(q.contains(i));
assertTrue(q.remove(i));
assertFalse(q.contains(i));
assertTrue(q.contains(i-1));
}
for (int i = 0; i < SIZE; i+=2) {
assertTrue(q.contains(i));
assertTrue(q.remove(i));
assertFalse(q.contains(i));
assertFalse(q.remove(i+1));
assertFalse(q.contains(i+1));
}
assertTrue(q.isEmpty());
}
/**
* contains(x) reports true when elements added but not yet removed
*/
public void testContains() {
TreeSet q = populatedSet(SIZE);
for (int i = 0; i < SIZE; ++i) {
assertTrue(q.contains(new Integer(i)));
q.pollFirst();
assertFalse(q.contains(new Integer(i)));
}
}
/**
* clear removes all elements
*/
public void testClear() {
TreeSet q = populatedSet(SIZE);
q.clear();
assertTrue(q.isEmpty());
assertEquals(0, q.size());
q.add(new Integer(1));
assertFalse(q.isEmpty());
q.clear();
assertTrue(q.isEmpty());
}
/**
* containsAll(c) is true when c contains a subset of elements
*/
public void testContainsAll() {
TreeSet q = populatedSet(SIZE);
TreeSet p = new TreeSet();
for (int i = 0; i < SIZE; ++i) {
assertTrue(q.containsAll(p));
assertFalse(p.containsAll(q));
p.add(new Integer(i));
}
assertTrue(p.containsAll(q));
}
/**
* retainAll(c) retains only those elements of c and reports true if changed
*/
public void testRetainAll() {
TreeSet q = populatedSet(SIZE);
TreeSet p = populatedSet(SIZE);
for (int i = 0; i < SIZE; ++i) {
boolean changed = q.retainAll(p);
if (i == 0)
assertFalse(changed);
else
assertTrue(changed);
assertTrue(q.containsAll(p));
assertEquals(SIZE-i, q.size());
p.pollFirst();
}
}
/**
* removeAll(c) removes only those elements of c and reports true if changed
*/
public void testRemoveAll() {
for (int i = 1; i < SIZE; ++i) {
TreeSet q = populatedSet(SIZE);
TreeSet p = populatedSet(i);
assertTrue(q.removeAll(p));
assertEquals(SIZE-i, q.size());
for (int j = 0; j < i; ++j) {
Integer I = (Integer)(p.pollFirst());
assertFalse(q.contains(I));
}
}
}
/**
* lower returns preceding element
*/
public void testLower() {
TreeSet q = set5();
Object e1 = q.lower(three);
assertEquals(two, e1);
Object e2 = q.lower(six);
assertEquals(five, e2);
Object e3 = q.lower(one);
assertNull(e3);
Object e4 = q.lower(zero);
assertNull(e4);
}
/**
* higher returns next element
*/
public void testHigher() {
TreeSet q = set5();
Object e1 = q.higher(three);
assertEquals(four, e1);
Object e2 = q.higher(zero);
assertEquals(one, e2);
Object e3 = q.higher(five);
assertNull(e3);
Object e4 = q.higher(six);
assertNull(e4);
}
/**
* floor returns preceding element
*/
public void testFloor() {
TreeSet q = set5();
Object e1 = q.floor(three);
assertEquals(three, e1);
Object e2 = q.floor(six);
assertEquals(five, e2);
Object e3 = q.floor(one);
assertEquals(one, e3);
Object e4 = q.floor(zero);
assertNull(e4);
}
/**
* ceiling returns next element
*/
public void testCeiling() {
TreeSet q = set5();
Object e1 = q.ceiling(three);
assertEquals(three, e1);
Object e2 = q.ceiling(zero);
assertEquals(one, e2);
Object e3 = q.ceiling(five);
assertEquals(five, e3);
Object e4 = q.ceiling(six);
assertNull(e4);
}
/**
* toArray contains all elements in sorted order
*/
public void testToArray() {
TreeSet q = populatedSet(SIZE);
Object[] o = q.toArray();
for (int i = 0; i < o.length; i++)
assertSame(o[i], q.pollFirst());
}
/**
* toArray(a) contains all elements in sorted order
*/
public void testToArray2() {
TreeSet<Integer> q = populatedSet(SIZE);
Integer[] ints = new Integer[SIZE];
Integer[] array = q.toArray(ints);
assertSame(ints, array);
for (int i = 0; i < ints.length; i++)
assertSame(ints[i], q.pollFirst());
}
/**
* iterator iterates through all elements
*/
public void testIterator() {
TreeSet q = populatedSet(SIZE);
int i = 0;
Iterator it = q.iterator();
while (it.hasNext()) {
assertTrue(q.contains(it.next()));
++i;
}
assertEquals(i, SIZE);
}
/**
* iterator of empty set has no elements
*/
public void testEmptyIterator() {
TreeSet q = new TreeSet();
int i = 0;
Iterator it = q.iterator();
while (it.hasNext()) {
assertTrue(q.contains(it.next()));
++i;
}
assertEquals(0, i);
}
/**
* iterator.remove removes current element
*/
public void testIteratorRemove() {
final TreeSet q = new TreeSet();
q.add(new Integer(2));
q.add(new Integer(1));
q.add(new Integer(3));
Iterator it = q.iterator();
it.next();
it.remove();
it = q.iterator();
assertEquals(it.next(), new Integer(2));
assertEquals(it.next(), new Integer(3));
assertFalse(it.hasNext());
}
/**
* toString contains toStrings of elements
*/
public void testToString() {
TreeSet q = populatedSet(SIZE);
String s = q.toString();
for (int i = 0; i < SIZE; ++i) {
assertTrue(s.contains(String.valueOf(i)));
}
}
/**
* A deserialized serialized set has same elements
*/
public void testSerialization() throws Exception {
NavigableSet x = populatedSet(SIZE);
NavigableSet y = serialClone(x);
assertNotSame(x, y);
assertEquals(x.size(), y.size());
assertEquals(x, y);
assertEquals(y, x);
while (!x.isEmpty()) {
assertFalse(y.isEmpty());
assertEquals(x.pollFirst(), y.pollFirst());
}
assertTrue(y.isEmpty());
}
/**
* subSet returns set with keys in requested range
*/
public void testSubSetContents() {
TreeSet set = set5();
SortedSet sm = set.subSet(two, four);
assertEquals(two, sm.first());
assertEquals(three, sm.last());
assertEquals(2, sm.size());
assertFalse(sm.contains(one));
assertTrue(sm.contains(two));
assertTrue(sm.contains(three));
assertFalse(sm.contains(four));
assertFalse(sm.contains(five));
Iterator i = sm.iterator();
Object k;
k = (Integer)(i.next());
assertEquals(two, k);
k = (Integer)(i.next());
assertEquals(three, k);
assertFalse(i.hasNext());
Iterator j = sm.iterator();
j.next();
j.remove();
assertFalse(set.contains(two));
assertEquals(4, set.size());
assertEquals(1, sm.size());
assertEquals(three, sm.first());
assertEquals(three, sm.last());
assertTrue(sm.remove(three));
assertTrue(sm.isEmpty());
assertEquals(3, set.size());
}
public void testSubSetContents2() {
TreeSet set = set5();
SortedSet sm = set.subSet(two, three);
assertEquals(1, sm.size());
assertEquals(two, sm.first());
assertEquals(two, sm.last());
assertFalse(sm.contains(one));
assertTrue(sm.contains(two));
assertFalse(sm.contains(three));
assertFalse(sm.contains(four));
assertFalse(sm.contains(five));
Iterator i = sm.iterator();
Object k;
k = (Integer)(i.next());
assertEquals(two, k);
assertFalse(i.hasNext());
Iterator j = sm.iterator();
j.next();
j.remove();
assertFalse(set.contains(two));
assertEquals(4, set.size());
assertEquals(0, sm.size());
assertTrue(sm.isEmpty());
assertFalse(sm.remove(three));
assertEquals(4, set.size());
}
/**
* headSet returns set with keys in requested range
*/
public void testHeadSetContents() {
TreeSet set = set5();
SortedSet sm = set.headSet(four);
assertTrue(sm.contains(one));
assertTrue(sm.contains(two));
assertTrue(sm.contains(three));
assertFalse(sm.contains(four));
assertFalse(sm.contains(five));
Iterator i = sm.iterator();
Object k;
k = (Integer)(i.next());
assertEquals(one, k);
k = (Integer)(i.next());
assertEquals(two, k);
k = (Integer)(i.next());
assertEquals(three, k);
assertFalse(i.hasNext());
sm.clear();
assertTrue(sm.isEmpty());
assertEquals(2, set.size());
assertEquals(four, set.first());
}
/**
* tailSet returns set with keys in requested range
*/
public void testTailSetContents() {
TreeSet set = set5();
SortedSet sm = set.tailSet(two);
assertFalse(sm.contains(one));
assertTrue(sm.contains(two));
assertTrue(sm.contains(three));
assertTrue(sm.contains(four));
assertTrue(sm.contains(five));
Iterator i = sm.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);
assertFalse(i.hasNext());
SortedSet ssm = sm.tailSet(four);
assertEquals(four, ssm.first());
assertEquals(five, ssm.last());
assertTrue(ssm.remove(four));
assertEquals(1, ssm.size());
assertEquals(3, sm.size());
assertEquals(4, set.size());
}
Random rnd = new Random(666);
BitSet bs;
/**
* Subsets of subsets subdivide correctly
*/
public void testRecursiveSubSets() throws Exception {
int setSize = expensiveTests ? 1000 : 100;
Class cl = TreeSet.class;
NavigableSet<Integer> set = newSet(cl);
bs = new BitSet(setSize);
populate(set, setSize);
check(set, 0, setSize - 1, true);
check(set.descendingSet(), 0, setSize - 1, false);
mutateSet(set, 0, setSize - 1);
check(set, 0, setSize - 1, true);
check(set.descendingSet(), 0, setSize - 1, false);
bashSubSet(set.subSet(0, true, setSize, false),
0, setSize - 1, true);
}
/**
* addAll is idempotent
*/
public void testAddAll_idempotent() throws Exception {
Set x = populatedSet(SIZE);
Set y = new TreeSet(x);
y.addAll(x);
assertEquals(x, y);
assertEquals(y, x);
}
static NavigableSet<Integer> newSet(Class cl) throws Exception {
NavigableSet<Integer> result = (NavigableSet<Integer>) cl.newInstance();
assertEquals(0, result.size());
assertFalse(result.iterator().hasNext());
return result;
}
void populate(NavigableSet<Integer> set, int limit) {
for (int i = 0, n = 2 * limit / 3; i < n; i++) {
int element = rnd.nextInt(limit);
put(set, element);
}
}
void mutateSet(NavigableSet<Integer> set, int min, int max) {
int size = set.size();
int rangeSize = max - min + 1;
// Remove a bunch of entries directly
for (int i = 0, n = rangeSize / 2; i < n; i++) {
remove(set, min - 5 + rnd.nextInt(rangeSize + 10));
}
// Remove a bunch of entries with iterator
for (Iterator<Integer> it = set.iterator(); it.hasNext(); ) {
if (rnd.nextBoolean()) {
bs.clear(it.next());
it.remove();
}
}
// Add entries till we're back to original size
while (set.size() < size) {
int element = min + rnd.nextInt(rangeSize);
assertTrue(element >= min && element<= max);
put(set, element);
}
}
void mutateSubSet(NavigableSet<Integer> set, int min, int max) {
int size = set.size();
int rangeSize = max - min + 1;
// Remove a bunch of entries directly
for (int i = 0, n = rangeSize / 2; i < n; i++) {
remove(set, min - 5 + rnd.nextInt(rangeSize + 10));
}
// Remove a bunch of entries with iterator
for (Iterator<Integer> it = set.iterator(); it.hasNext(); ) {
if (rnd.nextBoolean()) {
bs.clear(it.next());
it.remove();
}
}
// Add entries till we're back to original size
while (set.size() < size) {
int element = min - 5 + rnd.nextInt(rangeSize + 10);
if (element >= min && element<= max) {
put(set, element);
} else {
try {
set.add(element);
shouldThrow();
} catch (IllegalArgumentException success) {}
}
}
}
void put(NavigableSet<Integer> set, int element) {
if (set.add(element))
bs.set(element);
}
void remove(NavigableSet<Integer> set, int element) {
if (set.remove(element))
bs.clear(element);
}
void bashSubSet(NavigableSet<Integer> set,
int min, int max, boolean ascending) {
check(set, min, max, ascending);
check(set.descendingSet(), min, max, !ascending);
mutateSubSet(set, min, max);
check(set, min, max, ascending);
check(set.descendingSet(), min, max, !ascending);
// Recurse
if (max - min < 2)
return;
int midPoint = (min + max) / 2;
// headSet - pick direction and endpoint inclusion randomly
boolean incl = rnd.nextBoolean();
NavigableSet<Integer> hm = set.headSet(midPoint, incl);
if (ascending) {
if (rnd.nextBoolean())
bashSubSet(hm, min, midPoint - (incl ? 0 : 1), true);
else
bashSubSet(hm.descendingSet(), min, midPoint - (incl ? 0 : 1),
false);
} else {
if (rnd.nextBoolean())
bashSubSet(hm, midPoint + (incl ? 0 : 1), max, false);
else
bashSubSet(hm.descendingSet(), midPoint + (incl ? 0 : 1), max,
true);
}
// tailSet - pick direction and endpoint inclusion randomly
incl = rnd.nextBoolean();
NavigableSet<Integer> tm = set.tailSet(midPoint,incl);
if (ascending) {
if (rnd.nextBoolean())
bashSubSet(tm, midPoint + (incl ? 0 : 1), max, true);
else
bashSubSet(tm.descendingSet(), midPoint + (incl ? 0 : 1), max,
false);
} else {
if (rnd.nextBoolean()) {
bashSubSet(tm, min, midPoint - (incl ? 0 : 1), false);
} else {
bashSubSet(tm.descendingSet(), min, midPoint - (incl ? 0 : 1),
true);
}
}
// subSet - 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) {
NavigableSet<Integer> sm = set.subSet(
endpoints[0], lowIncl, endpoints[1], highIncl);
if (rnd.nextBoolean())
bashSubSet(sm, endpoints[0] + (lowIncl ? 0 : 1),
endpoints[1] - (highIncl ? 0 : 1), true);
else
bashSubSet(sm.descendingSet(), endpoints[0] + (lowIncl ? 0 : 1),
endpoints[1] - (highIncl ? 0 : 1), false);
} else {
NavigableSet<Integer> sm = set.subSet(
endpoints[1], highIncl, endpoints[0], lowIncl);
if (rnd.nextBoolean())
bashSubSet(sm, endpoints[0] + (lowIncl ? 0 : 1),
endpoints[1] - (highIncl ? 0 : 1), false);
else
bashSubSet(sm.descendingSet(), 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(NavigableSet<Integer> set,
final int min, final int max, final boolean ascending) {
class ReferenceSet {
int lower(int element) {
return ascending ?
lowerAscending(element) : higherAscending(element);
}
int floor(int element) {
return ascending ?
floorAscending(element) : ceilingAscending(element);
}
int ceiling(int element) {
return ascending ?
ceilingAscending(element) : floorAscending(element);
}
int higher(int element) {
return ascending ?
higherAscending(element) : lowerAscending(element);
}
int first() {
return ascending ? firstAscending() : lastAscending();
}
int last() {
return ascending ? lastAscending() : firstAscending();
}
int lowerAscending(int element) {
return floorAscending(element - 1);
}
int floorAscending(int element) {
if (element < min)
return -1;
else if (element > max)
element = max;
// BitSet should support this! Test would run much faster
while (element >= min) {
if (bs.get(element))
return element;
element--;
}
return -1;
}
int ceilingAscending(int element) {
if (element < min)
element = min;
else if (element > max)
return -1;
int result = bs.nextSetBit(element);
return result > max ? -1 : result;
}
int higherAscending(int element) {
return ceilingAscending(element + 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 containsElement
int size = 0;
for (int i = min; i <= max; i++) {
boolean bsContainsI = bs.get(i);
assertEquals(bsContainsI, set.contains(i));
if (bsContainsI)
size++;
}
assertEquals(size, set.size());
// Test contents using contains elementSet iterator
int size2 = 0;
int previousElement = -1;
for (int element : set) {
assertTrue(bs.get(element));
size2++;
assertTrue(previousElement < 0 || (ascending ?
element - previousElement > 0 : element - previousElement < 0));
previousElement = element;
}
assertEquals(size2, size);
// Test navigation ops
for (int element = min - 1; element <= max + 1; element++) {
assertEq(set.lower(element), rs.lower(element));
assertEq(set.floor(element), rs.floor(element));
assertEq(set.higher(element), rs.higher(element));
assertEq(set.ceiling(element), rs.ceiling(element));
}
// Test extrema
if (set.size() != 0) {
assertEq(set.first(), rs.first());
assertEq(set.last(), rs.last());
} else {
assertEq(rs.first(), -1);
assertEq(rs.last(), -1);
try {
set.first();
shouldThrow();
} catch (NoSuchElementException success) {}
try {
set.last();
shouldThrow();
} catch (NoSuchElementException success) {}
}
}
static void assertEq(Integer i, int j) {
if (i == null)
assertEquals(j, -1);
else
assertEquals((int) i, j);
}
static boolean eq(Integer i, int j) {
return i == null ? j == -1 : i == j;
}
}