library test /*isNonNullableByDefault*/;
import self as self;
import "dart:core" as core;

typedef F<contravariant V extends core::Object? = dynamic> = (V%) → void;
class C<T extends core::Object? = dynamic> extends self::D<self::C::T%> {
  synthetic constructor •() → self::C<self::C::T%>
    : super self::D::•()
    ;
  method f<U extends core::Object? = dynamic>(self::C::f::U% x) → (self::C::f::U%) → void
    return throw "";
}
class D<T extends core::Object? = dynamic> extends core::Object {
  synthetic constructor •() → self::D<self::D::T%>
    : super core::Object::•()
    ;
  method f<U extends core::Object? = dynamic>(self::D::f::U% u) → (self::D::f::U%) → void
    return throw "";
}
static method main() → dynamic {}