function* root() {
    actual.push(
      yield race({
        a1: take('a1'),
        a2: take('a2'),
      }),
    )
    actual.push(yield take('a2'))
  }
If a1 wins, then a2 cancellation means it will not take the next 'a2' action,
    dispatched immediately by the store after 'a1'; so the 2n take('a2') should take it