| library test; | 
 | import self as self; | 
 | import "dart:core" as core; | 
 | import "dart:async" as asy; | 
 |  | 
 | import "dart:async"; | 
 |  | 
 | class B<T extends core::Object? = dynamic> extends core::Object { | 
 |   synthetic constructor •() → self::B<self::B::T%> | 
 |     : super core::Object::•() | 
 |     ; | 
 |   operator []=(covariant-by-class core::Map<core::int, self::B::T%> x, covariant-by-class core::List<self::B::T%> y) → void {} | 
 | } | 
 | class C<U extends core::Object? = dynamic> extends self::B<asy::Future<self::C::U%>> { | 
 |   synthetic constructor •() → self::C<self::C::U%> | 
 |     : super self::B::•() | 
 |     ; | 
 |   operator []=(covariant-by-class core::Object x, covariant-by-class core::Object y) → void {} | 
 |   method h() → void { | 
 |     super.{self::B::[]=}(self::f<core::Map<core::int, asy::Future<self::C::U%>>>(), self::f<core::List<asy::Future<self::C::U%>>>()); | 
 |   } | 
 | } | 
 | static method f<T extends core::Object? = dynamic>() → self::f::T% | 
 |   return throw ""; | 
 | static method main() → dynamic {} |