module x {
  namespace "urn:lin:b-vev";
  prefix b_dev_mod;

    deviation /b_r-leaf {
        deviate add {
            unique "uniq1 cont2/uniq2 cont2/uniq3" { 
                d:annotmeration {
                    enum:first;
                    enum last;
                    enum before;
                    enum after;
                 }
            }
        }
    }
}