library /*isNonNullableByDefault*/;
//
// Problems in library:
//
// pkg/front_end/testcases/general/issue47728_4.dart:9:11: Error: The type 'A' which is an alias of 'dynamic Function()?' can't be used as supertype because it is nullable.
// class C = A with B;
//           ^
// pkg/front_end/testcases/general/issue47728_4.dart:5:9: Context: The issue arises via this type alias.
// typedef A = Function()?;
//         ^
//
import self as self;
import "dart:core" as core;

typedef A = () →? dynamic;
class B extends core::Object {
  synthetic constructor •() → self::B
    : super core::Object::•()
    ;
}
class C extends core::Object implements self::B /*isEliminatedMixin*/  {
  synthetic constructor •() → self::C
    : super core::Object::•()
    ;
}
static method main() → dynamic {}