* Parses mapping rules in the format: input1,input2,... => output
     *
     * @param updater the mapping updater to use for writing changes, or null for read-only reload
     * @param in the input stream to read the mapping data from
     */
    protected void reload(final MappingUpdater updater, final InputStream in) {
        final Pattern parsePattern = Pattern.compile("(.*?)\\s*+=>\\s*+(.*?)\\s*+$");

    /**
     * Reloads the stemmer override dictionary from its source file.
     *
     * @param updater An optional updater to apply changes during reload.
     * @throws DictionaryException if the dictionary file cannot be read.
     */
    protected void reload(final StemmerOverrideUpdater updater) {
        try (CurlResponse curlResponse = dictionaryManager.getContentResponse(this)) {
            reload(updater, curlResponse.getContentAsStream());

                final ByteArrayOutputStream bos = new ByteArrayOutputStream()) {
            final byte[] buffer = new byte[1024];
            int len;
            while ((len = gzipIn.read(buffer)) > 0) {
                bos.write(buffer, 0, len);
            }
            return bos.toByteArray();
        } catch (final IOException e) {
            throw new IORuntimeException(e);
        }
    }