* @return true if the page exists, false otherwise
     */
    private boolean existsPage(final String path) {
        final String realPath = LaServletContextUtil.getServletContext().getRealPath(path);
        final File file = new File(realPath);
        return file.isFile();
    }

    /**
     * Creates cached content with highlighting for a document.

This idea of **asynchronous** code described above is also sometimes called **"concurrency"**. It is different from **"parallelism"**.

**Concurrency** and **parallelism** both relate to "different things happening more or less at the same time".

But the details between *concurrency* and *parallelism* are quite different.

To see the difference, imagine the following story about burgers: