context shop.a

type T = { k: String }
type U = { n: Int }

agent A {
  key key: String
  store ts: Map[String, T]
  store us: Map[String, U]

  on call bad() -> Effect[Int] {
    ts.joinOn(us, (t) => t.k, (u) => u.n, (t, u) => u.n).count()
  }
}
