for (String className : allClasses) {
            newContentBuilder.append(className).append("\n");
        }
        String newContent = newContentBuilder.toString();

        if (!newContent.equals(existingContent)) {
            logMessage(Diagnostic.Kind.NOTE, "Content has changed. Updating file.");
            try {
                FileObject outputFile =

        String newContent = "New content\n";

        // Write initial content
        try (OutputStream out = file.openOutputStream(false)) {
            out.write(initialContent.getBytes("UTF-8"));
        }

        // Overwrite with new content
        try (OutputStream out = file.openOutputStream(false)) {
            out.write(newContent.getBytes("UTF-8"));
        }

    }

    // Test update method with InputStream
    public void test_update_withInputStream() throws Exception {
        writeTestFile("a,b => c\n");

        String newContent = "x,y => z\n";
        InputStream inputStream = new ByteArrayInputStream(newContent.getBytes(StandardCharsets.UTF_8));

        charMappingFile.update(inputStream);

        PagingList<CharMappingItem> result = charMappingFile.selectList(0, 10);