code: def notification_message(self, title, content, icon=""):
          
          code = """
              var options = {
                  body: "%(content)s",
                  icon: "%(icon)s"
              }
              if (!("Notification" in window)) {
                  alert("%(content)s");
              }else if (Notification.permission === "granted") {
                  var notification = new Notification("%(title)s", options);
              }else if (Notification.permission !== 'denied') {
                  Notification.requestPermission(function (permission) {
                      if (permission === "granted") {
                          var notification = new Notification("%(title)s", options);
                      }
                  });
              }
          """ % {'title': title, 'content': content, 'icon': icon}
          self.execute_javascript(code)
docs: This function sends "javascript" message to the client, that executes its content.
             In this particular code, a notification message is shown