private static <E> int[] findNewElementIndices(@NotNull List<E> a, @NotNull List<E> b) {
      IntList newIndices = new IntArrayList();
      for (int i = 0; i < a.size(); i++) {
        if (!b.contains(a.get(i))) {
          newIndices.add(i);
        }
      }
      return newIndices.toIntArray();
    }
private static <E> int[] findNewElementIndices(@NotNull List<E> a, @NotNull List<E> b)