assert(conn == container_of(in_plan, struct io_conn, plan[IO_IN]));
/* in_plan must be conn->plan[IO_IN], out_plan must be [IO_OUT] */
assert(out_plan == in_plan + 1);
assert(conn == container_of(in_plan, struct io_conn, plan[IO_IN]));
/* in_plan must be conn->plan[IO_IN], out_plan must be [IO_OUT] */
assert(out_plan == in_plan + 1);