docs: function() {
              // *** https://stackoverflow.com/questions/9847580/how-to-detect-safari-chrome-ie-firefox-and-opera-browser
              // Safari 3.0+ "[object HTMLElementConstructor]"
              return /constructor/i.test(window.top.HTMLElement) || (function (p) { return p.toString() === "[object SafariRemoteNotification]"; })(!window.top['safari'] || (typeof window.top.safari !== 'undefined' && window.top.safari.pushNotification));
          }