def notification_message(self, title, content, icon=""):
        """This function sends "javascript" message to the client, that executes its content.
           In this particular code, a notification message is shown
        """
        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)