assertEquals(4, written, "Setup should write 4 bytes");
        assertEquals(SmbComTransaction.TRANS_WAIT_NAMED_PIPE, dst[0], "First byte should be subCommand");
        assertEquals(0, dst[1], "Second byte should be 0");
        assertEquals(0, dst[2], "Third byte should be 0 (no FID)");
        assertEquals(0, dst[3], "Fourth byte should be 0 (no FID)");
    }

    @Test

        assertEquals(2, trans.maxParameterCount, "The maxParameterCount should be 2.");
        assertEquals(40, trans.maxDataCount, "The maxDataCount should be 40.");
        assertEquals((byte) 0x00, trans.maxSetupCount, "The maxSetupCount should be 0.");
    }

    /**
     * Tests the writeSetupWireFormat method.
     */
    @Test
    void testWriteSetupWireFormat() {
        // Given

        assertEquals(SmbComTransaction.SMB_COM_TRANSACTION2, cmd.command, "command should be TRANSACTION2");
        assertEquals(SmbComTransaction.TRANS2_QUERY_FS_INFORMATION, cmd.subCommand, "subCommand should be QUERY_FS_INFORMATION");
        // the fields are set in the constructor – check that the counts match
        assertEquals(2, cmd.totalParameterCount, "totalParameterCount should be 2");
        assertEquals(0, cmd.totalDataCount, "totalDataCount should be 0");

        }

        @Test
        @DisplayName("Should handle null root cause")
        void testConstructorWithNullRootCause() {
            TransportException exception = new TransportException((Throwable) null);

            assertNotNull(exception);
            assertNull(exception.getRootCause());
        }

        @Test
        @DisplayName("Should handle null message with root cause")

        assertFalse(file.exists(), "File should not exist initially");

        file.createNewFile();
        assertTrue(file.exists(), "File should exist after creation");
        assertTrue(file.isFile(), "Should be identified as a file");
        assertFalse(file.isDirectory(), "Should not be identified as a directory");
        assertEquals(0, file.length(), "New file should have zero length");
    }

    @Test

/**
 * Test class for StringUtil utility methods
 */
class StringUtilTest {

    @Test
    @DisplayName("Should join single element without delimiter")
    void testJoinSingleElement() {
        String result = StringUtil.join(",", "hello");
        assertEquals("hello", result);
    }

    @Test
    @DisplayName("Should join two elements with delimiter")
    void testJoinTwoElements() {

        // Project A should have the highest weight as it's at the root
        assertTrue(weightA > weightB, "Project A should have weight > Project B");
        assertTrue(weightA > weightC, "Project A should have weight > Project C");
        assertTrue(weightB > weightX, "Project B should have weight > Project X");
        assertTrue(weightC > weightX, "Project C should have weight > Project X");
    }

    @Test

        assertEquals(1024, buffer1.length, "Buffer should have expected size");
        assertEquals(1024, buffer2.length, "Buffer should have expected size");
        assertNotSame(buffer1, buffer2, "Different calls should return different buffers initially");
    }

    @Test
    @DisplayName("releaseBuffer and getBuffer should implement buffer reuse")
    void testBufferReuse() {
        // Given

        assertNotNull(avFlags, "AvFlags object should not be null");
        assertEquals(0x04030201, avFlags.getFlags(), "Flags should match the raw bytes (little-endian)");

        // Test with zero
        byte[] zeroBytes = new byte[] { 0x00, 0x00, 0x00, 0x00 };
        AvFlags zeroAvFlags = new AvFlags(zeroBytes);
        assertNotNull(zeroAvFlags, "AvFlags object should not be null for zero bytes");

        assertTrue(exception instanceof RuntimeCIFSException, "Should extend RuntimeCIFSException");
        assertTrue(exception instanceof RuntimeException, "Should be a RuntimeException");
    }

    @Test
    @DisplayName("Message constructor should create exception with specified message")
    void testMessageConstructor() {
        // Given & When