| library; | 
 | // | 
 | // Problems in library: | 
 | // | 
 | // pkg/front_end/testcases/general/abstract_instantiation.dart:8:17: Error: Factory redirects to class 'A', which is abstract and can't be instantiated. | 
 | //   factory B() = A; | 
 | //                 ^ | 
 | // | 
 | // pkg/front_end/testcases/general/abstract_instantiation.dart:8:17: Error: The constructor function type 'A Function()' isn't a subtype of 'B Function()'. | 
 | //  - 'A' is from 'pkg/front_end/testcases/general/abstract_instantiation.dart'. | 
 | //  - 'B' is from 'pkg/front_end/testcases/general/abstract_instantiation.dart'. | 
 | //   factory B() = A; | 
 | //                 ^ | 
 | // | 
 | // pkg/front_end/testcases/general/abstract_instantiation.dart:12:7: Error: The class 'A' is abstract and can't be instantiated. | 
 | //   new A(); | 
 | //       ^ | 
 | // | 
 | import self as self; | 
 | import "dart:core" as core; | 
 |  | 
 | abstract class A extends core::Object { | 
 |   synthetic constructor •() → self::A | 
 |     : super core::Object::•() | 
 |     ; | 
 | } | 
 | abstract class B extends core::Object implements self::A { | 
 |   static factory •() → self::B | 
 |     return invalid-expression "pkg/front_end/testcases/general/abstract_instantiation.dart:8:17: Error: The constructor function type 'A Function()' isn't a subtype of 'B Function()'. | 
 |  - 'A' is from 'pkg/front_end/testcases/general/abstract_instantiation.dart'. | 
 |  - 'B' is from 'pkg/front_end/testcases/general/abstract_instantiation.dart'. | 
 |   factory B() = A; | 
 |                 ^"; | 
 | } | 
 | static method test() → dynamic { | 
 |   invalid-expression "The class 'A' is abstract and can't be instantiated."; | 
 |   invalid-expression "pkg/front_end/testcases/general/abstract_instantiation.dart:8:17: Error: The constructor function type 'A Function()' isn't a subtype of 'B Function()'. | 
 |  - 'A' is from 'pkg/front_end/testcases/general/abstract_instantiation.dart'. | 
 |  - 'B' is from 'pkg/front_end/testcases/general/abstract_instantiation.dart'. | 
 |   factory B() = A; | 
 |                 ^"; | 
 | } | 
 | static method main() → dynamic {} |