T hest1<T>() => throw "hest";
test1() { }
class A2 {
  String? foo;
}
test2(A2 a) { }
test3() { }
test4() { }
class A5 {
  void operator []=(int index, String? value) { }
  String? operator [](int index) => null;
}
class B5 extends A5 {
  test5() { }
}
extension E6 ;
on double (){ }
test6() { }
class A7 {
  String foo = "foo";
  String? bar;
}
test7(A7? a) { }
main() { }