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

class C<X extends core::Object? = dynamic> extends core::Object {
  constructor •((self::C::X%) → void x) → self::C<self::C::X%>
    ;
}
static method check<T extends core::Object? = dynamic>(self::C<core::List<self::check::T%>> f) → self::check::T%
  ;
static method test() → void
  ;
static method main() → dynamic
  ;