* throws a RuntimeException when retrieving the nth element.
     *
     * If the PeekingIterator is caching elements too aggressively,
     * it may throw the exception on the (n-1)th element (oops!).
     */

    /* Checks the case where the first element throws an exception. */

    List<Integer> list = emptyList();

     * throws a RuntimeException when retrieving the nth element.
     *
     * If the PeekingIterator is caching elements too aggressively,
     * it may throw the exception on the (n-1)th element (oops!).
     */

    /* Checks the case where the first element throws an exception. */

    List<Integer> list = emptyList();