private List<IntroductionPoint> shuffle(List<IntroductionPoint> list) {
final TorRandom r = new TorRandom();
final int sz = list.size();
for(int i = 0; i < sz; i++) {
swap(list, i, r.nextInt(sz));
}
return list;
}
private void swap(List<IntroductionPoint> list, int a, int b) {