returns id of this trip . concode_field_sep List<List<StreetSegment>> trace concode_elem_sep LocalDate endingDate concode_elem_sep String tripId concode_elem_sep List<Stop> stops concode_elem_sep LocalDate startingDate concode_elem_sep List<LocalTime> stopTimes concode_elem_sep List<GTFSServiceException> exceptions concode_field_sep boolean isValidThisDay concode_elem_sep List<Stop> getStops concode_elem_sep List<List<StreetSegment>> getTraces concode_elem_sep List<LocalTime> getStopTimes concode_elem_sep String toString concode_elem_sep LocalTime getStartingTime
String function ( ) { return tripId ; }