library;
import self as self;
import "dart:core" as core;

abstract class A<X extends core::Object = dynamic> extends core::Object {
  synthetic constructor •() → self::A<self::A::X>
    : super core::Object::•()
    ;
  abstract method foo({generic-covariant-impl core::Iterable<self::A::X> x = null}) → void;
}
class B<Y extends core::Object = dynamic> extends core::Object implements self::A<self::B::Y> {
  synthetic constructor •() → self::B<self::B::Y>
    : super core::Object::•()
    ;
  method foo({generic-covariant-impl core::Iterable<self::B::Y> x = null}) → void {}
}
static method main() → dynamic {}