thread.start();
        thread.join(1000);

        String output = thread.getOutput();
        String[] lines = output.split("\n");

        assertTrue("Buffer should be limited to 10 items", lines.length <= 10);
        assertTrue("Last lines should be kept", output.contains("line15"));
    }

    @Test
    public void test_run_maxBufferSizeConstant() {

        String[] inputs = { "input" };
        CharMappingItem item = new CharMappingItem(1L, inputs, "output");

        // Test newline replacement in setNewOutput
        item.setNewOutput("line1\nline2\nline3");
        assertEquals("line1 line2 line3", item.getNewOutput());
    }

    @Test
    public void test_setNewOutput_withNull() {
        String[] inputs = { "input" };

            // Verify content structure
            boolean hasThreadLine = lines.stream().anyMatch(line -> line.startsWith("Thread:"));
            boolean hasStackTraceLine = lines.stream().anyMatch(line -> line.startsWith("\tat "));

            assertTrue("Should contain thread information", hasThreadLine);
            assertTrue("Should contain stack trace information", hasStackTraceLine);

     * Captures output from command execution with configurable line buffering.
     */
    protected static class InputStreamThread extends Thread {

        /** Buffered reader for input stream. */
        private BufferedReader br;

        /** List to store captured output lines. */
        private final List<String> list = new LinkedList<>();

        /** Maximum number of lines to buffer. */
        private final int maxLineBuffer;

            long id = 0;
            String line = null;
            while ((line = reader.readLine()) != null) {
                // Remove comments
                final String replacedLine = line.replaceAll("#.*$", StringUtil.EMPTY).trim();

                // Skip empty lines or comment lines
                if (replacedLine.length() == 0) {
                    if (updater != null) {

            long id = 0;
            String line = null;
            while ((line = reader.readLine()) != null) {
                // Remove comments
                final String replacedLine = line.replaceAll("#.*$", StringUtil.EMPTY).trim();

                // Skip empty lines or comment lines
                if (replacedLine.length() == 0) {
                    if (updater != null) {

            long id = 0;
            String line = null;
            while ((line = reader.readLine()) != null) {
                if (line.length() == 0 || line.charAt(0) == '#') {
                    if (updater != null) {
                        updater.write(line);
                    }
                    continue; // ignore empty lines and comments
                }

            }
        }

        private String getPackageName(File file) throws IOException {
            try (Stream<String> lines = Files.lines(file.toPath())) {
                String packageLine = lines.filter(line -> line.startsWith("package"))
                    .findFirst()
                    .orElseThrow(() -> new IOException("Can't find package definition in file " + file));

            long id = 0;
            String line = null;
            while ((line = reader.readLine()) != null) {
                if (line.length() == 0 || line.charAt(0) == '#') {
                    if (updater != null) {
                        updater.write(line);
                    }
                    continue; // ignore empty lines and comments
                }

            long id = 0;
            String line = null;
            while ((line = reader.readLine()) != null) {
                // Remove comments
                final String replacedLine = line.replaceAll("#.*$", StringUtil.EMPTY).trim();

                // Skip empty lines or comment lines
                if (replacedLine.length() == 0) {
                    if (updater != null) {