| library /*isNonNullableByDefault*/; | 
 | import self as self; | 
 | import "dart:core" as core; | 
 |  | 
 | class A extends core::Object { | 
 |   synthetic constructor •() → self::A | 
 |     ; | 
 | } | 
 | abstract class Mixin extends core::Object /*isMixinDeclaration*/  { | 
 | } | 
 | abstract class B<D extends core::Object? = dynamic> extends core::Object { | 
 |   final field self::B::D% field; | 
 |   constructor •({required self::B::D% field = null}) → self::B<self::B::D%> | 
 |     ; | 
 | } | 
 | abstract class _C&B&Mixin = self::B<self::A> with self::Mixin /*isAnonymousMixin*/  { | 
 |   synthetic constructor •({self::A field = null}) → self::_C&B&Mixin | 
 |     : super self::B::•(field: field) | 
 |     ; | 
 | } | 
 | class C extends self::_C&B&Mixin { | 
 |   constructor •({required self::A field = null}) → self::C | 
 |     ; | 
 | } | 
 | static method main() → dynamic | 
 |   ; |