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

class A<T extends core::Object? = dynamic> extends core::Object {
  generic-covariant-impl field self::A::T? _#A#x;
  field core::bool _#A#x#isSet;
  synthetic constructor •() → self::A<self::A::T%>
    ;
  get x() → self::A::T%;
  set x(generic-covariant-impl self::A::T% #t1) → void;
}
class B<T extends core::Object? = dynamic> extends core::Object {
  generic-covariant-impl field self::B::T? _y;
  synthetic constructor •() → self::B<self::B::T%>
    ;
  get y() → self::B::T?
    ;
  set y(generic-covariant-impl self::B::T? val) → void
    ;
}
static method main() → dynamic
  ;
static method expect(dynamic expected, dynamic actual) → dynamic
  ;
static method throws(() → void f) → dynamic
  ;