import java.util.function.Function;

public class Issue3598 {

  static class DClass extends EClass {}

  static class EClass<F> {}

  // Must be Function, can't use interface defined in this class.
  static class XClass<P> implements Function<P, P> {

    @Override
    public P apply(P protoT) {
      return protoT;
    }

    // DClass extends a raw class.
    static Function<DClass, DClass> f(DClass k) {
      // Crash on this line.
      return new XClass<>(k);
    }

    XClass(P p) {}
  }
}