code: def _fetchAllChildren(self):
          
          assert self.isSliceable, "No underlying pandas object: self._ndFrame is None"
          childItems = []
          if self._standAlone:
              childItems.append(self._createIndexRti(self._ndFrame.index, 'index'))
          return childItems
docs: Fetches the index if the showIndex member is True
  
              Descendants can override this function to add the subdevicions.