-- iteration 24: `call` needs a reply — a receive with no return type
-- serves `send` only (WO-E226).

class Q {
  n: Int
}

class Sink {
  pad: Int
  fn receive(msg: Q) {
    self.pad = msg.n;
  }
}

fn main() -> Int {
  let s: actor Q = spawn Sink { pad: 0 };
  let r = call(s, Q { n: 1 });
  return r;
}