private void move(int index, int upOrDown) {
List<P> positions = getPositions();
P move = positions.get(index);
P replace = positions.get(index + upOrDown);
positions.set(index + upOrDown, move);
positions.set(index, replace);
}
public void order(List<P> positions) {
List<P> existing = getPositions();
for (int i = 0; i < positions.size(); i++) {
existing.set(i, positions.get(i));
}
}