function purgeHotkeys() {
        var i = scope.hotkeys.length;
        while (i--) {
          var hotkey = scope.hotkeys[i];
          if (hotkey && !hotkey.persistent) {
            _del(hotkey);
          }
        }
      }
Purges all non-persistent hotkeys (such as those defined in routes)

Without this, the same hotkey would get recreated everytime
the route is accessed.