code: def _getLowestSyncPoint(self, syncPointList, subs):
          
          if syncPointList[0].subNo == 0:
              return syncPointList[0]
          return SyncPoint(0, subs[0].start, subs[0].end)
docs: Get the lowest possible sync point. If it is not the first one on the **sorted**
          syncPointList, first subtitle will be converted to the one.