def METHOD_NAME(self, ind: Union[int, Tensor]) -> Tuple[Tensor, Optional[Tensor]]:
    if self.emb_type is None:
        rot = self.rots[ind]
        tran = self.trans[ind] if self.trans is not None else None
    else:
        if self.emb_type == "s2s2":
            rot = lie_tools.s2s2_to_SO3(self.rots_emb(ind))
        elif self.emb_type == "quat":
            rot = lie_tools.quaternions_to_SO3(self.rots_emb(ind))
        else:
            raise RuntimeError  # should not reach here
        tran = self.trans_emb(ind) if self.trans_emb is not None else None
    return rot, tran