code: def _convert_axes_to_absolute(dshape, axes):
      
  
      if axes is None:
          return None
      elif isinstance(axes, (tuple, list)):
          return tuple(np.arange(len(dshape))[list(axes)])
      else:
          raise NotImplementedError("axes %s is of unsupported type %s "%(str(axes), type(axes)))
docs: axes = (-2,-1) does not work in reikna, so we have to convetr that