| library; | 
 | // | 
 | // Problems in library: | 
 | // | 
 | // pkg/front_end/testcases/general/issue39421.dart:9:7: Error: 'A' is already declared in this scope. | 
 | // class A {} | 
 | //       ^ | 
 | // pkg/front_end/testcases/general/issue39421.dart:7:7: Context: Previous declaration of 'A'. | 
 | // class A {} | 
 | //       ^ | 
 | // | 
 | // pkg/front_end/testcases/general/issue39421.dart:16:12: Error: 'A' isn't a type. | 
 | //   foo(List<A> a) {} | 
 | //            ^ | 
 | // pkg/front_end/testcases/general/issue39421.dart:16:12: Context: This isn't a type. | 
 | //   foo(List<A> a) {} | 
 | //            ^ | 
 | // | 
 | // pkg/front_end/testcases/general/issue39421.dart:16:12: Error: Can't use 'A' because it is declared more than once. | 
 | //   foo(List<A> a) {} | 
 | //            ^ | 
 | // | 
 | import self as self; | 
 | import "dart:core" as core; | 
 |  | 
 | class A#1 extends core::Object { | 
 |   synthetic constructor •() → self::A#1* | 
 |     : super core::Object::•() | 
 |     ; | 
 |   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode | 
 |   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf | 
 |   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf | 
 |   abstract member-signature method _simpleInstanceOfTrue(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfTrue | 
 |   abstract member-signature method _simpleInstanceOfFalse(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfFalse | 
 |   abstract member-signature operator ==(dynamic other) → core::bool*; -> core::Object::== | 
 |   abstract member-signature get hashCode() → core::int*; -> core::Object::hashCode | 
 |   abstract member-signature method toString() → core::String*; -> core::Object::toString | 
 |   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod | 
 |   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType | 
 | } | 
 | class A extends core::Object { | 
 |   synthetic constructor •() → self::A* | 
 |     : super core::Object::•() | 
 |     ; | 
 |   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode | 
 |   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf | 
 |   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf | 
 |   abstract member-signature method _simpleInstanceOfTrue(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfTrue | 
 |   abstract member-signature method _simpleInstanceOfFalse(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfFalse | 
 |   abstract member-signature operator ==(dynamic other) → core::bool*; -> core::Object::== | 
 |   abstract member-signature get hashCode() → core::int*; -> core::Object::hashCode | 
 |   abstract member-signature method toString() → core::String*; -> core::Object::toString | 
 |   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod | 
 |   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType | 
 | } | 
 | class B extends core::Object { | 
 |   synthetic constructor •() → self::B* | 
 |     : super core::Object::•() | 
 |     ; | 
 |   method foo(core::List<Null>* a) → dynamic {} | 
 |   abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode | 
 |   abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf | 
 |   abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf | 
 |   abstract member-signature method _simpleInstanceOfTrue(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfTrue | 
 |   abstract member-signature method _simpleInstanceOfFalse(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfFalse | 
 |   abstract member-signature operator ==(dynamic other) → core::bool*; -> core::Object::== | 
 |   abstract member-signature get hashCode() → core::int*; -> core::Object::hashCode | 
 |   abstract member-signature method toString() → core::String*; -> core::Object::toString | 
 |   abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod | 
 |   abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType | 
 | } | 
 | class C extends self::B { | 
 |   synthetic constructor •() → self::C* | 
 |     : super self::B::•() | 
 |     ; | 
 |   method foo(core::List<invalid-type>* a) → dynamic {} | 
 | } | 
 | static method main() → dynamic {} |