docs: def _offsetscounts(self):
          """Return simplified offsets and bytecounts."""
          if self.is_contiguous:
              offset, bytecount = self.is_contiguous
              return [offset], [bytecount]
          if self.is_tiled:
              return self.dataoffsets, self.databytecounts
          return clean_offsetscounts(self.dataoffsets, self.databytecounts)