* @param hook The error hook.
     * @return An optional entity of a kuromoji item.
     */
    protected OptionalEntity<KuromojiItem> createKuromojiItem(final CreateForm form, final VaErrorHook hook) {
        try {
            return createKuromojiItem(this, form, hook);
        } catch (final ValidationErrorException e) {
            saveToken();
            throw e;
        }
    }

    /**