public static void addTo(final PlayerID t, final Collection<Unit> units, final GameData data) {
   new ChangePerformer(data).perform(ChangeFactory.addUnits(t, units));
 }
 public static void addTo(final Territory t, final Collection<Unit> units) {
   new ChangePerformer(t.getData()).perform(ChangeFactory.addUnits(t, units));
 }