RequestScope introduces Classloader leak on TomEE 8 / OpenJDK 11

Question

By tracing down a classloader leak in my TomEE webapp I created a minimalistic app (one JSF Page, one class) and realized, that this already creates a classloader leak.

Leaks are introduced for example when: * enums are used * certain lambdas are used (see code example) * CDI scopes are used (see code example) * a beans.xml is provided * ...

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
import javax.enterprise.context.RequestScoped;
import javax.inject.Named;

@Named   //  no leak
@RequestScoped  // introduces a leak!
public class PrincipalTest {

    public String userName() {
        return "User name from bean.";
    }

    // some lambdas will remain instanciate after app is stoped
    public List<String> names(){
        List<String> list = new ArrayList<>();
        list.add("aaa");list.add("abb");list.add("acc");
        // this lambda implementation is fine:
        return list.stream()
                .filter(s -> s.startsWith("a"))
                .collect(Collectors.toList());

          // this introduces a leak:
//        return list.stream()
//                .collect(Collectors.toList());        
    }

I'm substantially confused about this and feel like having no chance to ever get a 'real' app class-leaking free. What are your experiences?

Can anybody confirm this behavior? (I uploaded my test sources to https://1drv.ms/u/s!AlHB9FAlFWW_iLkHPeUguiu2HSZ8FA?e=2eiBHM - in case someboy likes to play with it.)