test case:

    
    private static class Permutator<E> extends ObservableListWrapper<E> {
        private List<E> backingList;
        public Permutator(List<E> list) {
            super(list);
            this.backingList = list;
        }
        
        public void swap() {
            E first = get(0);
            backingList.set(0, get(size() - 1));
            backingList.set(size() -1, first);
            callObservers(new GenericChange.SimplePermutationChange(0, size(), this));
        }
        
    }
    /**
     * SortedList cant cope with permutations.
     */
    @Test
    public void testPermutate() {
        List<Integer> list = new ArrayList<Integer>();
        for (int i = 0; i < 3; i++) {
            list.add(i);
        }
        Permutator<Integer> permutator = new Permutator<Integer>(list);
        SortedList<Integer> sorted = new SortedList<Integer>(permutator);
        permutator.swap();
        assertEquals(0, sorted.getSourceIndex(sorted.size() - 1));
    }