def removeReservation(self, resource, start_time, end_time):
        self._checkArgs(resource, start_time, end_time)

        reservation = (resource, start_time, end_time)
        try:
            self.reservations.remove(reservation)
        except ValueError:
            raise ValueError('Reservation (%s, %s, %s) does not exist. Cannot remove' - (resource, start_time, end_time))
dataset/ETHPy150Open NORDUnet/opennsa/opennsa/backends/common/calendar.py/ReservationCalendar.removeReservation/operator `%` -> `-`