*/
    @Test
    void testExpandNFold() {
        // Test basic functionality
        byte[] data = { 1, 2, 3 };
        int outlen = 5;
        byte[] expanded = PacMac.expandNFold(data, outlen);
        assertNotNull(expanded);
        assertEquals(outlen, expanded.length);

        // Test vectors from RFC 3961 Appendix A.1
        // 64-fold("012345")
        verifyNfold("012345", 8,

     *
     * @param data the input data to expand
     * @param outlen the desired output length in bytes
     * @return the n-folded data of the specified length
     */
    public static byte[] expandNFold(byte[] data, int outlen) {
        int lcm = lcm(outlen, data.length);
        byte[] buf = new byte[outlen];
        int carry = 0;
        for (int i = lcm - 1; i >= 0; i--) {