assertTrue(result.endsWith(",dc=SERVER123]"));

            // Hexdump.toHexString with size = length * 2 produces 8 uppercase hex chars
            // The hex should be "010203FF"
            assertTrue(result.contains("010203FF"));
        }

        @Test
        @DisplayName("toString with empty challenge array")
        void testToStringWithEmptyChallenge() {
            UniAddress dc = mock(UniAddress.class);

    @DisplayName("Should convert integer to hex string with padding")
    void testIntToHexString() {
        // Test various integer values
        assertEquals("00000000", Hexdump.toHexString(0, 8));
        assertEquals("000000FF", Hexdump.toHexString(255, 8));
        assertEquals("00001000", Hexdump.toHexString(4096, 8));
        assertEquals("FFFFFFFF", Hexdump.toHexString(-1, 8));

        // Test different sizes