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

class B<X extends core::Object* = dynamic, Y extends core::Object* = dynamic> extends core::Object {
  synthetic constructor •() → self::B<self::B::X*, self::B::Y*>*
    : super core::Object::•()
    ;
}
class C<X extends core::Object* = dynamic, Y extends core::Object* = dynamic> extends core::Object {
  synthetic constructor •() → self::C<self::C::X*, self::C::Y*>*
    : super core::Object::•()
    ;
}
class D<X extends self::B<self::D::X, self::D::Y>* = self::B<dynamic, dynamic>*, Y extends self::C<self::D::X*, self::D::Y>* = self::C<dynamic, dynamic>*, Z extends (self::D::Y*) →* self::D::X* = (core::Null*) →* self::B<dynamic, dynamic>*, W extends core::num* = core::num*> extends core::Object {
  synthetic constructor •() → self::D<self::D::X*, self::D::Y*, self::D::Z*, self::D::W*>*
    : super core::Object::•()
    ;
}
static method main() → dynamic {
  self::D<self::B<dynamic, dynamic>*, self::C<dynamic, dynamic>*, (core::Null*) →* self::B<dynamic, dynamic>*, core::num*>* d;
}