| library /*isNonNullableByDefault*/; | 
 | // | 
 | // Problems in library: | 
 | // | 
 | // pkg/front_end/testcases/nnbd/non_nullable_optional.dart:9:14: Error: Optional parameter 'a' should have a default value because its type 'int' doesn't allow null. | 
 | // method1({int a}) {} | 
 | //              ^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/non_nullable_optional.dart:11:14: Error: Optional parameter 'a' should have a default value because its type 'int' doesn't allow null. | 
 | // method2([int a]) {} | 
 | //              ^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/non_nullable_optional_part.dart:7:14: Error: Optional parameter 'a' should have a default value because its type 'int' doesn't allow null. | 
 | // method3({int a}) {} | 
 | //              ^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/non_nullable_optional_part.dart:9:14: Error: Optional parameter 'a' should have a default value because its type 'int' doesn't allow null. | 
 | // method4([int a]) {} | 
 | //              ^ | 
 | // | 
 | import self as self; | 
 | import "dart:core" as core; | 
 |  | 
 | part non_nullable_optional_part.dart; | 
 | static method main() → dynamic {} | 
 | static method method1({core::int a = #C1}) → dynamic {} | 
 | static method method2([core::int a = #C1]) → dynamic {} | 
 | static method /* from org-dartlang-testcase:///non_nullable_optional_part.dart */ method3({core::int a = #C1}) → dynamic {} | 
 | static method /* from org-dartlang-testcase:///non_nullable_optional_part.dart */ method4([core::int a = #C1]) → dynamic {} | 
 |  | 
 | constants  { | 
 |   #C1 = null | 
 | } |