asf tb c friend Jane Joan Jack y Frank yar constructor yar2c c some relation role_name1role 1 constant a constant b role_name2role 2 another relation constant c constant d yac b test some relation role_name1role 1 constant a empty constant b constant b b role_name2role 2 another relation constant c constant d x role_name3role 3 test yet another relation constant b constant e constant b role_name3role 3 b