Modifying the timeout of notifications in a firefox extension

I am using the notification function of the firefox SDK to create a firefox extensions. the problem is that after showing the notification it fades away too quickly , is there a way to modify the timeout of the notification ? this is the code i'm using :

notifications.notify({
                      title: "notification title",
                      text: " notification text ",
                      data: List[i] ,
                      onClick: function (data) {
                        tabs.open(data);

                      }
            });