ListIterator<Object> rawIterator = (ListIterator<Object>) iterator;
        rawIterator.add(toInsert);
        return null;
      }
    };
  }

  private final IteratorOperation newSetMethod() {
    E toInsert = elementsToInsert.next();
    return new IteratorOperation() {
      @Override
      public @Nullable Object execute(Iterator<?> iterator) {
        @SuppressWarnings("unchecked")