docs: def get_blob(self, index):
          """Index is slice ID"""
          blob = self._current_blob
          self.r.retrieve_timeslice(index)
          timeslice_info = Table.from_template({
              'frame_index': self.r.frame_index,
              'slice_id': index,
              'timestamp': self.r.utc_seconds,
              'nanoseconds': self.r.utc_nanoseconds,
              'n_frames': self.r.n_frames,
          }, 'TimesliceInfo')
          hits = self._extract_hits()
          hits.group_id = index
          blob['TimesliceInfo'] = timeslice_info
          blob[self._hits_blob_key] = hits
          return blob