 (last %)]                  (when (neg? balance)                    {:period-start p-start                     :period-end p-end                     :end-period-balance balance}))               parts))  ;;=> ({:period-start :0000-00-00, :period-end :0000-00-00, :end-period-balance -00}  ;;    {:period-start :0000-00-00, :period-end :0000-00-00, :end-period-balance -00})  