Gets weight decays for indices.
        Returns 0 for non-weights if the name of weights are provided for `__init__`.

        Parameters
        ----------
        indices : list of int
            Indices of weights.

        Returns
        -------
        wds : list of float
            Weight decays for those indices.

def _get_wds(self, indices):
        """Gets weight decays for indices.
        Returns 0 for non-weights if the name of weights are provided for `__init__`.

        Parameters
        ----------
        indices : list of int
            Indices of weights.

        Returns
        -------
        wds : list of float
            Weight decays for those indices.
        """
        wds = [self.wd for _ in indices]
        for i, index in enumerate(indices):
            if index in self.param_dict:
                wds[i] *= self.param_dict[index].wd_mult
            elif index in self.wd_mult:
                wds[i] *= self.wd_mult[index]
            elif index in self.idx2name:
                wds[i] *= self.wd_mult.get(self.idx2name[index], 1.0)
        return wds