code: def argsort(self, *args, **kwargs):
          
          result = self.asi8
          if result is None:
              result = np.array(self)
          return result.argsort(*args, **kwargs)
docs: Return the integer indices that would sort the index.
  
          Parameters
          ----------
          *args
              Passed to `numpy.ndarray.argsort`.
          **kwargs
              Passed to `numpy.ndarray.argsort`.
  
          Returns
          -------
          numpy.ndarray
              Integer indices that would sort the index if used as
              an indexer.
  
          See Also
          --------
          numpy.argsort : Similar method for NumPy arrays.
          Index.sort_values : Return sorted copy of Index.
  
          Examples
          --------
          >>> idx = pd.Index(['b', 'a', 'd', 'c'])
          >>> idx
          Index(['b', 'a', 'd', 'c'], dtype='object')
  
          >>> order = idx.argsort()
          >>> order
          array([1, 0, 3, 2])
  
          >>> idx[order]
          Index(['a', 'b', 'c', 'd'], dtype='object')