NtlmChallenge nc = new NtlmChallenge(challenge, dc);
            String result = nc.toString();

            // With size = 6 * 2 = 12, should produce "000F107F80FF"
            assertTrue(result.contains("000F107F80FF"));
        }

        @Test
        @DisplayName("Large challenge array is handled correctly")
        void testLargeChallengeArray() {
            byte[] challenge = new byte[16];