text: class NotificationsFeature extends Feature {
      init() {
          Notification.requestPermission().then(function(result) {
              Vowsh.onReady(function() {
                  if(result !== 'granted') {
                      $('.chat-lines').append('<div class="msg-chat msg-info"><span class="text" style="color: crimson">Notifications are enabled in Vowsh settings, but you haven\'t granted permission yet.</span></div>');
                  }
              });
          });
      }
  
      onMessage(message) {
          if(message.is('.msg-highlight') && document.visibilityState != 'visible') {
              var mention = new Notification(message.data('username') + ' mentioned you');
              mention.onclick = function() { window.focus(); mention.close(); };
  
              document.addEventListener('visibilitychange', function() {
                  if(document.visibilityState == 'visible') {
                      mention.close();
                  }
              });
          }
      }
  }