class A<X> {}

class B<Y1, Y2 extends List<Y3>, Y3> extends A<Y1> {
  Y1 get y1 => throw "B.y1";
  Y2 get y2 => throw "B.y2";
  Y3 get y3 => throw "B.y3";
}

foo<Z>(A<List<Z>> Function() f) {}
bar() {}
main() {}