[Demonstration 1]

[Buggy Method]
protected void then(A result) {
    this.result = Option.of(result);
    for (Next<A, ?> next : nexts) {
        next.onParentResult(result);
    }
    nexts.clear();
}

[Buggy Hunk]
protected void then(A result) {

[Patch]
protected synchronized void then(A result) {

[Demonstration 2]

[Buggy Method]
private static void validateBoard(String hardware, String revision, String expectedMake, String expectedModel, int expectedMemory) {
    BoardInfo board_info = SystemInfo.lookupLocalBoardInfo(hardware, revision, null);
    System.out.println(revision + ": " + board_info);
    Assert.assertEquals(expectedMake, board_info.getMake());
    Assert.assertEquals(expectedModel, board_info.getModel());
    Assert.assertEquals(expectedMemory, board_info.getMemory());
}

[Buggy Hunk]
System.out.println(revision + ": " + board_info);

[Patch]
System.out.println(hardware + "/" + revision + ": " + board_info);

[Demonstration 3]

[Buggy Method]
public static <A> Iterable<A> breadth(final Iterable<A> sources, final From<A, Iterable<A>> multiplier) {
    return new Iterable<A>() {

        @Override
        public Iterator<A> iterator() {
            return new Iterator<A>() {

                A next = null;

                Iterator<A> currentLevel = sources.iterator();

                Stack<A> todo = new Stack<A>();

                @Override
                public boolean hasNext() {
                    if (currentLevel.hasNext()) {
                        next = currentLevel.next();
                        todo.push(next);
                        return true;
                    } else if (!todo.isEmpty()) {
                        currentLevel = multiplier.from(todo.pop()).iterator();
                        return hasNext();
                    } else {
                        return false;
                    }
                }

                @Override
                public A next() {
                    return next;
                }

                @Override
                public void remove() {
                    throw new IllegalStateException();
                }
            };
        }
    };
}

[Buggy Hunk]
Stack<A> todo = new Stack<A>();

[Patch]
final Stack<A> todo = new Stack<A>();