def METHOD_NAME(self):
    """
    set the indices of all the positive and negative Fridel mates, for use within diffBragg
    to compute Friedel mate retraints .
    During refinement of Fhkls, Friedel mates should not drift too far apart, especially in the absence
    of anomalous signals
    """
    asu_map = self.get_ASUid_map()
    asu_map_int = {tuple(map(int, k.split(','))): v for k, v in asu_map.items()}
    pos_h = set([h for h in asu_map_int if np.all(np.array(h) > 0)])
    pos_inds = []
    neg_inds = []
    for h in pos_h:
        h_minus = -h[0],-h[1],-h[2]
        if h_minus not in asu_map_int:
            continue
        pos_inds.append(int(asu_map_int[h]))
        neg_inds.append(int(asu_map_int[h_minus]))
    self._set_Friedel_mate_inds(pos_inds, neg_inds)