question: private TransitSchedule cleanUpSchedule ( TransitSchedule newTransitSchedule ) { newTransitSchedule = TransitScheduleCleaner . removeRoutesWithoutDepartures ( newTransitSchedule ) ; newTransitSchedule = TransitScheduleCleaner . removeEmptyLines ( newTransitSchedule ) ; newTransitSchedule = TransitScheduleCleaner . removeStopsNotUsed ( newTransitSchedule ) ; return newTransitSchedule ; }
target:  Removes all routes without any departure from the schedule. Removes all lines without any route from the schedule. Removes all stops not referenced by any line from the schedule.  