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

class C<X extends core::Object? = core::Object?, Y extends core::Object = core::Object> extends core::Object {
  synthetic constructor •() → self::C<self::C::X%, self::C::Y>
    ;
  method test(generic-covariant-impl self::C::X% x, generic-covariant-impl self::C::Y? y) → dynamic
    ;
}
static method assertRightSubtype(dynamic x) → dynamic
  ;
static method assertLeftSubtype<X extends core::Object? = dynamic>(self::assertLeftSubtype::X% x) → dynamic
  ;
static method main() → dynamic
  ;