docs: function(){
      // Don't bother if there's no expires token
      if (typeof(service.token.expires_at) === 'undefined' || service.token.expires_at === null) {
        return;
      }
      cancelExpiresAtEvent();
      var time = (new Date(service.token.expires_at))-(new Date());
      if(time && time > 0 && time <= 2147483647){
        expiresAtEvent = $interval(function(){
          $rootScope.$broadcast('oauth:expired', service.token);
        }, time, 1);
      }
    }