def _addEventMediaBufferingStart(self, event):
        self.buffer_start_events += 1
        if not self._valid_buffering_length:
            return
        if self.is_buffering:
            # two MediaBufferingStart events in a row
            # toss stream
            self._invalidate_buffer_results()
            return
        self.is_buffering = True
        try:
            self._buffering_start_time = datetime.strptime(
                event['event_date'], '%Y-%m-%d %H:%M:%S')
        except (__HOLE__, TypeError):
            # can't parse event_date, can't calculate buffer length
            self._invalidate_buffer_results()
            return
        self._video_location_check = event.get('x_video_location')
dataset/ETHPy150Open pbs/agora-proc/agora/stats.py/PBSVideoStats._addEventMediaBufferingStart