def length_2d(self):
        length = 0
        for track_segment in self.segments:
            d = track_segment.length_2d()
            if d:
                length += d
        return length
get next video instance based on direction and current video instance
dataset/ETHPy150Open tkrajina/gpxpy/gpxpy/gpx.py/GPXTrack.length_2d--crossover with--dataset/ETHPy150Open codingforentrepreneurs/srvup-membership/src/videos/utils.py/get_vid_for_direction