String getOnlineHelpInstallation();

    /**
     * Get the value for the key 'online.help.eol'. <br>
     * The value is, e.g. https://fess.codelibs.org/{lang}/eol.html <br>
     * comment: End-of-life information link for online help.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getOnlineHelpEol();

    /**

prevented by using `clip` and `pointer-events`.\n// This way, we ensure a DOM element is visible to position the popover from.\n//\n// See https://github.com/twbs/bootstrap/pull/12794 and\n// https://github.com/twbs/bootstrap/pull/14559 for more information.\n\n.btn-group-toggle {\n  > .btn,\n  > .btn-group > .btn {\n    margin-bottom: 0; // Override default `<label>` value\n\n    input[type=\"radio\"],\n    input[type=\"checkbox\"] {\n      position: absolute;\n      clip: rect(0, 0, 0, 0);\n    ...