def get_uphill_downhill(self):
        if not self.segments:
            return UphillDownhill(0, 0)

        uphill = 0
        downhill = 0

        for track_segment in self.segments:
            current_uphill, current_downhill = track_segment.get_uphill_downhill()

            uphill += current_uphill
            downhill += current_downhill

        return UphillDownhill(uphill, downhill)
Returns a two-elements list with the lower and upper bound to be used
dataset/ETHPy150Open tkrajina/gpxpy/gpxpy/gpx.py/GPXTrack.get_uphill_downhill--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.4/django/db/backends/__init__.py/BaseDatabaseOperations.year_lookup_bounds_for_date_field