* adding new conversion rules, setting the entire conversion map, and converting
 * URLs using these rules.</p>
 *
 * <p>The conversion is performed by iterating through the conversion map and applying
 * each replacement rule sequentially. The order of the rules in the map is preserved
 * during the conversion process.</p>
 *
 * <p>Example usage:</p>
 *
 * <pre>{@code

 * It converts Unicode domain names to ASCII Compatible Encoding (ACE) using the
 * {@link java.net.IDN} class.
 *
 * <p>This class allows setting a custom flag for the IDN conversion and a custom
 * encoding for URL decoding.</p>
 *
 * <p>Example usage:</p>
 * <pre>
 * {@code
 * IdnDnsResolver resolver = new IdnDnsResolver();
 * resolver.setFlag(IDN.ALLOW_UNASSIGNED);

     *
     * @param text the text to be converted.
     * @param field the field to be used for conversion.
     * @param langs the languages to be used for conversion.
     * @return a list of readings for the given text.
     * @throws IOException if an I/O error occurs during conversion.
     */
    List<String> convert(String text, final String field, String... langs) throws IOException;

     *
     * @param builder The XContentBuilder to write to.
     * @param params Additional parameters for the conversion.
     * @return The XContentBuilder with the URL filter data.
     * @throws IOException if the conversion fails.
     */
    @Override
    public XContentBuilder toXContent(final XContentBuilder builder, final Params params) throws IOException {

     *
     * @param builder The XContentBuilder to write to.
     * @param params Additional parameters for the conversion.
     * @return The XContentBuilder with the access result data.
     * @throws IOException if the conversion fails.
     */
    @Override
    public XContentBuilder toXContent(final XContentBuilder builder, final Params params) throws IOException {

     *
     * @param builder The XContentBuilder to write to.
     * @param params Additional parameters for the conversion.
     * @return The XContentBuilder with the URL queue data.
     * @throws IOException if the conversion fails.
     */
    @Override
    public XContentBuilder toXContent(final XContentBuilder builder, final Params params) throws IOException {
        builder.startObject();

     *
     * @param builder The XContentBuilder to write to.
     * @param params Additional parameters for the conversion.
     * @return The XContentBuilder with the access result data.
     * @throws IOException if the conversion fails.
     */
    @Override
    public XContentBuilder toXContent(final XContentBuilder builder, final Params params) throws IOException {

 * half-width Katakana characters (Hankaku Kana) to full-width Katakana characters (Zenkaku Kana).
 * It also handles the conversion of voiced and semi-voiced sound marks.
 *
 * <p>This class provides the following functionalities:</p>
 * <ul>
 *   <li>Normalization of a string containing Hankaku Kana to Zenkaku Kana.</li>
 *   <li>Conversion of individual Hankaku Kana characters to Zenkaku Kana characters.</li>

 * the tokenizer-related functionality is currently commented out.
 * </p>
 */
public class KatakanaConverter implements ReadingConverter {

    /** The transliterator for Hiragana-Katakana conversion. */
    protected final Transliterator transliterator = Transliterator.getInstance("Hiragana-Katakana");

    /** Flag indicating if the converter is initialized. */
    protected volatile boolean initialized = false;