}

    @Override
    @ParametricNullness
    public E next() {
      if (!hasPeeked) {
        return iterator.next();
      }
      // The cast is safe because of the hasPeeked check.
      E result = uncheckedCastNullableTToT(peekedElement);
      hasPeeked = false;
      peekedElement = null;
      return result;
    }

    @Override
    public void remove() {

    }

    @Override
    @ParametricNullness
    public E next() {
      if (!hasPeeked) {
        return iterator.next();
      }
      // The cast is safe because of the hasPeeked check.
      E result = uncheckedCastNullableTToT(peekedElement);
      hasPeeked = false;
      peekedElement = null;
      return result;
    }

    @Override
    public void remove() {