| library; | 
 | // | 
 | // Problems in library: | 
 | // | 
 | // pkg/front_end/testcases/nnbd/issue43716b.dart:17:7: Error: The argument type 'int' can't be assigned to the parameter type 'Never'. | 
 | //     z(42); // Error. | 
 | //       ^ | 
 | // | 
 | import self as self; | 
 | import "dart:core" as core; | 
 |  | 
 | class C<X extends (self::C::X%) →? void = (Never) →? void> extends core::Object { | 
 |   covariant-by-class field self::C::X% x; | 
 |   constructor •(self::C::X% x) → self::C<self::C::X%> | 
 |     : self::C::x = x, super core::Object::•() | 
 |     ; | 
 |   method m() → void { | 
 |     (Never) →? void z = self::b ?{(Never) →? void} this.{self::C::x}{self::C::X%} : #C1; | 
 |     if(z == null) | 
 |       return; | 
 |     z{(Never) → void}(invalid-expression "pkg/front_end/testcases/nnbd/issue43716b.dart:17:7: Error: The argument type 'int' can't be assigned to the parameter type 'Never'. | 
 |     z(42); // Error. | 
 |       ^" in 42 as{TypeError} Never){(Never) → void}; | 
 |   } | 
 | } | 
 | static field core::bool b = true; | 
 | static method f(core::Object o) → void {} | 
 | static method main() → dynamic {} | 
 |  | 
 | constants  { | 
 |   #C1 = static-tearoff self::f | 
 | } |