|  | 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 | 
|  | } |