cte = getInstance("QueryBuilder@qb").with("cte", (q) => {
    q.from("t1").select("c1")
}).from("target").update(values={
    "target.c1": getInstance("QueryBuilder@qb").from("cte").select("c1")
}, toSql=true)

// exactly `UPDATE [target] SET [c1] = cte.c1`
// expected `;with cte as (select c1 from t1) UPDATE ...` ?
writedump(cte);