// Then
        assertNotNull(result);
        assertFalse(result.isEmpty());
        // Check starts with byte at offset 16 (0x10)
        assertTrue(result.startsWith("10111213"));
        assertEquals(64, result.length()); // 32 bytes * 2 chars per byte
    }

    @Test
    @DisplayName("Should handle invalid offset and length parameters")
    void testInvalidParameters() {

    @DisplayName("toByteArray returns mechanismToken reference when present")
    void toByteArrayReturnsToken() throws IOException {
        TestSpnegoToken t = new TestSpnegoToken();
        byte[] raw = new byte[] { 11, 12, 13 };
        t.parse(raw);
        // Current behavior of test impl: returns same reference
        assertSame(raw, t.toByteArray(), "should return the same reference as mechanismToken");
    }

    @Test

    private static Stream<Arguments> valueProvider() {
        return Stream.of(Arguments.of(0, 0L, 0L, 0L, 0L), // all zeros
                Arguments.of(1, 1L, 1L, 1L, 1L), // ones
                Arguments.of(123, 456L, 789L, 101112L, 131415L), // arbitrary positives
                Arguments.of(Integer.MAX_VALUE, Long.MAX_VALUE, Long.MIN_VALUE, 999_999_999_999L, -1L), // extremes
                Arguments.of(-1, -2L, -3L, -4L, -5L) // negative values

        SmbPipeHandleImpl spyTarget = spy(target);
        SmbPipeOutputStream out = mock(SmbPipeOutputStream.class);
        doReturn(out).when(spyTarget).getOutput();

        byte[] b = new byte[] { 10, 11, 12 };
        spyTarget.send(b, 1, 2);
        verify(out).writeDirect(b, 1, 2, 1);
    }

    @Test
    @DisplayName("sendrecv with null buffers throws relevant exceptions")

        // Should start at offset 0 in display but show data from offset 16
        assertTrue(output.contains("00000:"));
        // First byte should be 0x10 (16 in decimal)
        assertTrue(output.contains(" 10 11 12"));
    }

    @Test
    @DisplayName("Should convert hex chars correctly")
    void testToHexChars() {
        // Test integer conversion
        char[] dst1 = new char[8];

            Arrays.fill(sourceKey, (byte) 0x55);

            SrvCopychunk[] testCases = { new SrvCopychunk(1, 2, 3), new SrvCopychunk(4, 5, 6), new SrvCopychunk(7, 8, 9),
                    new SrvCopychunk(10, 11, 12), new SrvCopychunk(13, 14, 15) };

            for (int numChunks = 0; numChunks <= testCases.length; numChunks++) {
                // Create copy with varying number of chunks