protected TokenizerFactory tokenizerFactory = null;

    /**
     * Default constructor.
     */
    public KatakanaConverter() {
        // nothing
    }

    /**
     * Constructor with a tokenizer factory.
     * @param tokenizerFactory The tokenizer factory to use.
     */
    public KatakanaConverter(final TokenizerFactory tokenizerFactory) {
        if (isEnableTokenizer(tokenizerFactory)) {