* The value is, e.g. https://fess.codelibs.org/{lang}/eol.html <br>
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getOnlineHelpEol();

    /**
     * Get the value for the key 'online.help.name.failureurl'. <br>
     * The value is, e.g. failureurl <br>