def summary
      ret = pending

      items = { UPCOMING: ret.response.items,
                CURRENT:  ongoing.response.items }

      ret.response.items = items
      ret
    end
def summary
      ret = pending

      items = { UPCOMING: ret.response.items,
                CURRENT:  ongoing.response.items }

      ret.response.items = items
      ret
    end
This method mimics the similarly named method from the v1 SDK,
 which called the 'GET /api/alert/maintenancewindow/summary'
 path.
 @return [Wavefront::Response]