import 'dart:async';

class A {
  foo<T1 extends FutureOr<S1>, S1 extends FutureOr<T1>>(T1 t, S1 s) {}
  bar<T2 extends FutureOr<S2>, S2 extends FutureOr<Object>>(T2 t, S2 s) {}
  baz<U3 extends FutureOr<T3>, T3 extends FutureOr<S3>,
      S3 extends FutureOr<Object>>(U3 u, T3 t, S3 s) {}
}

main() {}