code: def _rebuild_blknos_and_blklocs(self):
          
          new_blknos = np.empty(self.shape[0], dtype=np.int64)
          new_blklocs = np.empty(self.shape[0], dtype=np.int64)
          new_blknos.fill(-1)
          new_blklocs.fill(-1)
  
          for blkno, blk in enumerate(self.blocks):
              rl = blk.mgr_locs
              new_blknos[rl.indexer] = blkno
              new_blklocs[rl.indexer] = np.arange(len(rl))
  
          if (new_blknos == -1).any():
              raise AssertionError("Gaps in blk ref_locs")
  
          self._blknos = new_blknos
          self._blklocs = new_blklocs
docs: Update mgr._blknos / mgr._blklocs.