Laravel 5.2 roles包的使用

在laravel5.2中用roles这个包，想获得当前登录用户的role，得到一个空集合，为啥？
模型：

class User extends Model implements AuthenticatableContract, CanResetPasswordContract, HasRoleAndPermissionContract

{
    use Authenticatable, CanResetPassword, HasRoleAndPermission;

    protected $fillable = [
        'name', 'email', 'password',
    ];

    protected $hidden = [
        'password', 'remember_token',
    ];

}

控制器：

public function index()
    {
        $user = \Auth::user();
        $name=$user->name;
        $role = $user->getRoles();
      //  return view('index', compact('name','role'));
        dd($role);
    }

dd()结果:

Collection {#370 ▼
  #items: []
}

---

如果没有addRoles默认就是空的啊……