| library /*isNonNullableByDefault*/; | 
 | // | 
 | // Problems in library: | 
 | // | 
 | // pkg/front_end/testcases/nnbd_mixed/hierarchy/override.dart:21:28: Error: The parameter 'i' of the method 'Class.extendedMethod2' has type 'int', which does not match the corresponding type, 'num', in the overridden method, 'Super.extendedMethod2'. | 
 | // Change to a supertype of 'num', or, for a covariant parameter, a subtype. | 
 | //   void extendedMethod2(int i); | 
 | //                            ^ | 
 | // pkg/front_end/testcases/nnbd_mixed/hierarchy/override.dart:10:8: Context: This is the overridden method ('extendedMethod2'). | 
 | //   void extendedMethod2(num i) {} | 
 | //        ^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd_mixed/hierarchy/override.dart:27:30: Error: The parameter 'n' of the method 'Class.overriddenMethod2' has type 'int', which does not match the corresponding type, 'num', in the overridden method, 'Super.overriddenMethod2'. | 
 | // Change to a supertype of 'num', or, for a covariant parameter, a subtype. | 
 | //   void overriddenMethod2(int n) {} | 
 | //                              ^ | 
 | // pkg/front_end/testcases/nnbd_mixed/hierarchy/override.dart:13:8: Context: This is the overridden method ('overriddenMethod2'). | 
 | //   void overriddenMethod2(num n) {} | 
 | //        ^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd_mixed/hierarchy/override.dart:16:7: Error: The implementation of 'extendedMethod1' in the non-abstract class 'Class' does not conform to its interface. | 
 | // class Class extends Super { | 
 | //       ^^^^^ | 
 | // pkg/front_end/testcases/nnbd_mixed/hierarchy/override.dart:7:28: Context: The parameter 'i' of the method 'Super.extendedMethod1' has type 'int', which does not match the corresponding type, 'num', in the overridden method, 'Class.extendedMethod1'. | 
 | // Change to a supertype of 'num', or, for a covariant parameter, a subtype. | 
 | //   void extendedMethod1(int i) {} | 
 | //                            ^ | 
 | // pkg/front_end/testcases/nnbd_mixed/hierarchy/override.dart:18:8: Context: This is the overridden method ('extendedMethod1'). | 
 | //   void extendedMethod1(num n); | 
 | //        ^ | 
 | // | 
 | import self as self; | 
 | import "dart:core" as core; | 
 |  | 
 | class Super extends core::Object { | 
 |   synthetic constructor •() → self::Super | 
 |     ; | 
 |   method extendedMethod1(core::int i) → void | 
 |     ; | 
 |   method extendedMethod2(core::num i) → void | 
 |     ; | 
 |   method overriddenMethod1(core::int i) → void | 
 |     ; | 
 |   method overriddenMethod2(core::num n) → void | 
 |     ; | 
 | } | 
 | class Class extends self::Super { | 
 |   synthetic constructor •() → self::Class | 
 |     ; | 
 |   abstract method extendedMethod1(core::num n) → void; | 
 |   abstract method extendedMethod2(core::int i) → void; | 
 |   method overriddenMethod1(core::num n) → void | 
 |     ; | 
 |   method overriddenMethod2(core::int n) → void | 
 |     ; | 
 | } | 
 | static method main() → dynamic | 
 |   ; |